Sample records for black liquor bark from the National Library of Energy Beta (NLEBeta)

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A concentrated aqueous blackliquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a blackliquor drying zone at its upper part, a blackliquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the blackliquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

Blackliquor gasification (BLG) is being considered primarily as an option for production of biofuels in recent years due to the focus on the transport sector’s high oil dependence and climate impact. BLG may be performed either at low temperatures or at high temperatures, based on whether the process is conducted above or below the melting temperature range of the spent pulping chemicals. The development of various BLG technologies—SCA-Billerud process, the Copeland recovery process, Weyerhaeuser’s process, the St. Regis hydropyrolysis process, the Texaco process, VTT’s circulating fluidized bed BLG process, Babcock and Wilcox’s bubbling fluidized bed gasification process, NSP process (Ny Sodahus Process), DARS (Direct Alkali Recovery System) process, BLG with direct causticization, Manufacturing and Technology Conversion International fluidized bed gasification, Chemrec gasification, catalytic hydrothermal gasification of blackliquor—is discussed in this chapter. The two main technologies under development are pressurized gasification and atmospheric gasification, being commercialized by Chemrec AB and ThermoChem Recovery International, respectively.

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) blackliquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of blackliquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by blackliquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for blackliquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing blackliquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) blackliquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of blackliquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by blackliquor gasification. Refractory materials were selected or developed that reacted with the gasifier environment to form protective surfaces in-situ; and were functionally-graded to give the best combination of thermal, mechanical and physical properties and chemical stability; and are relatively inexpensive, reliable repair materials. Material development was divided into 2 tasks: Task 1 was development and property determinations of improved and existing refractory systems for blackliquor containment. Refractory systems of interest include magnesium aluminate and barium aluminate for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO2 and SiC. Task 2 was finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing blackliquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) blackliquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of blackliquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by blackliquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for blackliquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing blackliquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) blackliquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of blackliquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by blackliquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for blackliquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing blackliquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) blackliquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of blackliquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by blackliquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective surfaces in-situ; are functionally-graded to give the best combination of thermal, mechanical, and physical properties and chemical stability; or are relatively inexpensive, reliable repair materials. Material development will be divided into 2 tasks: Task 1, Development and property determinations of improved and existing refractory systems for blackliquor containment. Refractory systems of interest include magnesia aluminate and baria aluminate spinels for binder materials, both dry and hydratable, and materials with high alumina contents, 85-95 wt%, aluminum oxide, 5.0-15.0 wt%, and BaO, SrO, CaO, ZrO and SiC. Task 2, Finite element analysis of heat flow and thermal stress/strain in the refractory lining and steel shell of existing and proposed vessel designs. Stress and strain due to thermal and chemical expansion has been observed to be detrimental to the lifespan of existing blackliquor gasifiers. The thermal and chemical strain as well as corrosion rates must be accounted for in order to predict the lifetime of the gasifier containment materials.

This continuation of earlier work reports fuel nitrogen release for blackliquors at two temperatures during pyrolysis of single droplets in an oxygen-free environment. Approximately half of the 20--60% fuel nitrogen released was ammonia and half was molecular nitrogen. The total amount of fixed nitrogen released during pyrolysis was almost linearly proportional to the liquor nitrogen content. The yield of fixed nitrogen for birch liquors was significantly higher than for pine liquors, and the yield for bagasse liquor was extremely high.

This Final Technical Report provides an account of the project for the demonstration of BlackLiquor Gasification at Georgia-Pacific LLC's Big Island, VA facility. This report covers the period from May 5, 2000 through November 30, 2006.

On June 14--17, 1988 the participants and invited guests of the Cooperative Program in Kraft Recovery gathered in Charleston, South Carolina, to review progress on four major blackliquor research programs being executed at the Institute of Paper Chemistry, the University of Maine, the National Bureau of Standards, and the University of Florida. These programs include: (1) BlackLiquor Properties; (2) BlackLiquor Droplet Formation; (3) BlackLiquor Nozzle Evaluation; and (4) BlackLiquor Combustion. In addition to the objectives of previous meetings, this meeting made a direct attempt to gather ideas on how to improve our ability to move from new technology concepts to commercial implementation. Also attached is the agenda for the Charleston meeting. The first two days were involved with updates and reviews of the four major blackliquor programs. A half day was spent discussing pathways to implementation and developing thoughts on what industry, DOE and academia could do to facilitate commercial implementation of the research results. This publication is a summary of the presentations made in Charleston and the industry responses to the research work. Readers are cautioned that the contents are in-progress updates on the status of the research and do not represent referred technical papers. Any questions regarding the content should be referred to the principal investigators of the project.

In July 1985, Champion International completed a study of kraft blackliquor gasification and use of the product gases in a combined cycle cogeneration system based on gas turbines. That study indicated that gasification had high potential as an alternative to recovery boiler technology and offered many advantages. This paper describes the design of the plant, the construction of the pilot plant, and finally presents data from operation of the plant.

The overall objective of the program was to develop correlations to predict physical properties within requirements of engineering precision from a knowledge of pulping conditions and of kraft blackliquor composition, if possible. These correlations were to include those relating thermodynamic properties to pulping conditions and liquor composition. The basic premise upon which the research was based is the premise that blackliquor behaves as a polymer solution. This premise has proven to be true, and has been used successfully in developing data reduction methods and in interpreting results. A three phase effort involving pulping, analysis of liquor composition, and measurement of liquor properties was conducted.

Obstacles hindering the commercialization of blackliquor gasification are discussed. The most important of them include financial risks, protection of the gasifier, increase in the causticizing demand, tar condensation, hot gas cleanup, and steam deficit. Gasification system demands significant capital investment. The high temperature and pressure and the alkaline conditions create aggressive environment. Protection from an aggressive environment is very important in the operation of a gasifier because it determines the lifetime and hence the feasibility of gasification as a technology as a whole.

Environmental impact of blackliquor gasification (BLG) is discussed. Biofuels from a BLG process excel in terms of well-to-wheel carbon dioxide emission reduction and energy efficiency. Forest biorefinery utilizing gasification (in a blackliquor gasification combined cycle (BLGCC) configuration) rather than a Tomlinson boiler is predicted to produce significantly fewer pollutant emissions due to the intrinsic characteristics of the BLGCC technology. Syngas cleanup conditioning removes a considerable amount of contaminants and gas turbine combustion is more efficient and complete than boiler combustion. Also, there could be reductions in pollutant emissions and hazardous wastes resulting from cleaner production of chemicals and fuels that are now manufactured using fossil energy resources. Production of power, fuels, chemicals, and other products from biomass resources creates a net zero generation of carbon dioxide as plants are renewable carbon sinks. BLG whether conducted at high or low temperatures is still superior to the current recovery boiler combustion technology. Implementation of IGCC power plants will cause net savings in cooling water requirements and net reductions in wastewater discharges. The most significant environmental impact caused by BLG will occur in air emissions. The overall reduction of Total reduced sulphur (TRS) gases using gasification technology will also reduce odor, which will improve public acceptance of pulp and paper mills, particularly in populated areas.

MOLTEN SALT CORROSION OF SUPERHEATERS IN BLACKLIQUOR RECOVERY BOILERS John Bohling, University Goodman Introduction In the papermaking industry, blackliquor recovery boilers burn blackliquor into the superheater region of the boiler, where the salt-deposit, or smelt, forms a scale on the superheater tubes.1

This paper reports on biomass gasifications. The main by-product in pulp making is blackliquor from virgin fiber; the main by-product in paper recycling is fiber residue. Although the blackliquor is recycled for chemical and energy recovery, safety problems plague the boilers currently used to do this. The fiber residue is usually transported to a landfill. The system being developed by MTCI will convert blackliquor and fiber residue into a combustible gas, which can then be used for a wide variety of thermal or power generation applications.

A wide variety of experimental techniques have been used in this work, and many of these have been developed completely or improved significantly in the course of the research done during this program. Therefore, it is appropriate to describe these techniques in detail as a reference for future workers so that the techniques can be used in future work with little additional effort or so that the results reported from this program can be compared better with future results from other work. In many cases, the techniques described are for specific analytical instruments. It is recognized that these may be superseded by future developments and improvements in instrumentation if a complete description of techniques used successfully in the past on other instrumentation is available. The total pulping and liquor preparation research work performed included chip and white liquor preparation, digestion, pulp washing, liquor and wash recovery, liquor sampling, weak liquor concentration in two steps to about 45--50% solids with an intermediate soap skimming at about 140F and 27--30% solids, determination of pulp yield and Kappa number, determination of total liquor solids, and a check on the total material balance for pulping. All other research was performed either on a sample of the weak blackliquor (the combined blackliquor and washes from the digester) or on the skimmed liquor that had been concentrated.

MTCI/StoneChem developed a steam reforming, fluidized bed gasification technology for biomass. DOE supported the demonstration of this technology for gasification of spent wood pulping liquor (or 'blackliquor') at Georgia-Pacific's Big Island, Virginia mill. The present pre-commercial R&D project addressed the opportunities as well as identified negative aspects when the MTCI/StoneChem gasification technology is integrated in a pulp mill production facility. The opportunities arise because blackliquor gasification produces sulfur (as H{sub 2}S) and sodium (as Na{sub 2}CO{sub 3}) in separate streams which may be used beneficially for improved pulp yield and properties. The negative aspect of kraft blackliquor gasification is that the amount of Na{sub 2}CO{sub 3} which must be converted to NaOH (the so called causticizing requirement) is increased. This arises because sulfur is released as Na{sub 2}S during conventional kraft blackliquor recovery, while during gasification the sodium associated Na{sub 2}S is partly or fully converted to Na{sub 2}CO{sub 3}. The causticizing requirement can be eliminated by including a TiO{sub 2} based cyclic process called direct causticization. In this process blackliquor is gasified in the presence of (low sodium content) titanates which convert Na{sub 2}CO{sub 3} to (high sodium content) titanates. NaOH is formed when contacting the latter titanates with water, thereby eliminating the causticizing requirement entirely. The leached and low sodium titanates are returned to the gasification process. The project team comprised the University of Maine (UM), North Carolina State University (NCSU) and MTCI/ThermoChem. NCSU and MTCI are subcontractors to UM. The principal organization for the contract is UM. NCSU investigated the techno-economics of using advanced pulping techniques which fully utilize the unique cooking liquors produced by steam reforming of blackliquor (Task 1). UM studied the kinetics and agglomeration problems of the conversion of Na{sub 2}CO{sub 3} to (high sodium) titanates during gasification of blackliquor in the presence of (low sodium) titanates or TiO{sub 2} (Task 2). MTCI/ThermoChem tested the performance and operability of the combined technology of steam reforming and direct causticization in their Process Development Unit (PDU) (Task 3). The specific objectives were: (1) to investigate how split sulfidity and polysulfide (+ AQ) pulping can be used to increase pulp fiber yield and properties compared to conventional kraft pulping; (2) to determine the economics of blackliquor gasification combined with these pulping technologies in comparison with conventional kraft pulping and blackliquor recovery; (3) to determine the effect of operating conditions on the kinetics of the titanate-based direct causticization reaction during blackliquor gasification at relatively low temperatures ({le} 750 C); (4) to determine the mechanism of particle agglomeration during gasification of blackliquor in the presence of titanates at relatively low temperatures ({le} 750 C); and (5) to verify performance and operability of the combined technology of steam reforming and direct causticization of blackliquor in a pilot scale fluidized bed test facility.

The laboratory immersion test system built and operated at ORNL was found to successfully screen samples from numerous refractory suppliers, including both commercially available and experimental materials. This system was found to provide an accurate prediction of how these materials would perform in the actual gasifier environment. Test materials included mullites, alumino-silicate bricks, fusion-cast aluminas, alumina-based and chrome-containing mortars, phosphate-bonded mortars, coated samples provided under an MPLUS-funded project, bonded spinels, different fusion-cast magnesia-alumina spinels with magnesia content ranging from 2.5% to about 60%, high-MgO castable and brick materials, spinel castables, and alkali-aluminate materials. This testing identified several candidate material systems that perform well in the New Bern gasifier. Fusion-cast aluminas were found to survive for nearly one year, and magnesia-alumina spinels have operated successfully for 18 months and are expected to survive for two years. Alkali-aluminates and high-MgO-content materials have also been identified for backup lining applications. No other material with a similar structure and chemical composition to that of the fusion-cast magnesium-aluminum spinel brick currently being used for the hot-face lining is commercially available. Other materials used for this application have been found to have inferior service lives, as previously discussed. Further, over 100 laboratory immersion tests have been performed on other materials (both commercial and experimental), but none to date has performed as well as the material currently being used for the hot-face lining. Operating experience accumulated with the high-temperature gasifier at New Bern, North Carolina, has confirmed that the molten alkali salts degrade many types of refractories. Fusion-cast alumina materials were shown to provide a great improvement in lifetime over materials used previously. Further improvement was realized with fusion-cast magnesia-alumina spinel refractory, which appears to be the most resistant to degradation found to date, exhibiting over a year of service life and expected to be capable of over two years of service life. Regarding the use of refractory mortar, it was found that expansion of the current chrome-alumina mortar when subjected to blackliquor smelt is likely contributing to the strains seen on the vessel shell. Additionally, the candidate high-alumina mortar that was originally proposed as a replacement for the current chrome-alumina mortar also showed a large amount of expansion when subjected to molten smelt. A UMR experimental mortar, composed of a phosphate bonded system specifically designed for use with fusion-cast magnesium-aluminum spinel, was found to perform well in the molten smelt environment. Strain gauges installed on the gasifier vessel shell provided valuable information about the expansion of the refractory, and a new set of strain gauges and thermocouples has been installed in order to monitor the loading caused by the currently installed spinel refractory. These results provide information for a direct comparison of the expansion of the two refractories. Measurements to date suggest that the fusion-cast magnesia-alumina spinel is expanding less than the fusion-cast {alpha}/{beta}-alumina used previously. A modified liquor nozzle was designed and constructed to test a number of materials that should be more resistant to erosion and corrosion than the material currently used. Inserts made of three erosion-resistant metallic materials were fabricated, along with inserts made of three ceramic materials. The assembled system was sent to the New Bern mill for installation in the gasifer in 2005. Following operation of the gasifier using the modified nozzle, inserts should be removed and analyzed for wear by erosion/corrosion. Although no materials have been directly identified for sensor/thermocouple protection tubes, several of the refractory material systems identified for lining material applications may be applicable for use in this

Sample records for black liquor bark from the National Library of Energy Beta (NLEBeta)

Note: This page contains sample records for the topic "black liquor bark" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.

Abstract The pulp and paper sector is intensive in the use of energy, and presents a high participation in the industrial context, specially based in the blackliquor, a renewable source generated in the pulp process. Blackliquor gasification is not still completely dominated; however, it has the potential of becoming an important alternative for the pulp and paper sector. In this article, the traditional steam cycle based on chemical recovery and biomass boilers associated to backpressure/extraction turbine is compared to blackliquor gasification combined cycle schemes, associated to biomass boiler, considering the technical and economic attractiveness of capturing and sequestering CO2. Results show that despite its interesting exergetic efficiency, the adoption CO2 capture system for BLGCC did not prove to be attractive under the prescribed conditions without major incentive.

Fuel nitrogen release during blackliquor pyrolysis is high. There is only minor release during the drying stage. Ammonia is the main fixed nitrogen species formed. The rate of fixed nitrogen release increases with increasing temperature. The level of fixed nitrogen released by birch liquor is almost twice the level for pine liquor. Assuming complete conversion to NO, fixed nitrogen yields gave NO concentrations near typically measured values for flue gases in full scale recovery boilers. The purpose of this work was to gain more detailed information about the behavior of the fuel nitrogen in blackliquor combustion. The work focused on the pyrolysis or devolatilization of the combustion process. Devolatilization is the stage at which the majority (typically 50--80%) of the liquor organics release from a fuel particle or droplet as gaseous species due to the rapid destruction of the organic macromolecules in the liquor. In this paper, the authors use the terms devolatilization and pyrolysis interchangeably with no difference in their meaning.

January 7, 2000 January 7, 2000 DOE Opens Competition for BlackLiquor/Biomass Gasification Program Intended to Boost Efficiency, Reduce Greenhouse Gases from Pulp and Paper Mills A new competition begun this week by the Department of Energy could make the pulp and paper mills of the 21st century cleaner and more energy efficient by demonstrating improved technologies to convert their spent cooking liquor streams into new sources of energy. The advanced processes would also simultaneously recover and recycle pulping chemicals. MORE INFO Download the solicitation The department's National Energy Technology Laboratory has issued a call for projects to demonstrate advanced ways to gasify the blackliquor or biomass of pulp and paper mills. The gases can be more easily cleaned of

Fuel NOx and thermal NOx were measured in combustion gases from blackliquors in two laboratory furnaces. Combustion at 950 C in air (8% O[sub 2]) produced NOx concentrations of 40-80ppm. Combustion at 950 C in synthetic air containing no nitrogen (21% 0[sub 2] in Ar) produced the same result, demonstrating that all of the NOx produced during combustion at 950 C was fuel NOx. Formation of fuel NOx increased moderately with increasing temperature in the range of 800-1,000 C, but temperature sensitivity of fuel NOx was much less than that of thermal NOx. The results imply that the major source of NOx in recovery furnace emissions is the fuel NOx in recovery furnace formed by conversion of liquor-bound nitrogen during combustion. This is consistent with thermal NOx theory, which postulates that black-liquor combustion temperatures are too low to generate significant amounts of thermal NOx.

The University of Utah's project 'Investigation of Pressurized Entrained-Flow Kraft BlackLiquor Gasification in an Industrially Relevant Environment' (U.S. DOE Cooperative Agreement DE-FC26-04NT42261) was a response to U.S. DOE/NETL solicitation DE-PS36-04GO94002, 'Biomass Research and Development Initiative' Topical Area 4-Kraft BlackLiquor Gasification. The project began September 30, 2004. The objective of the project was to improve the understanding of blackliquor conversion in high pressure, high temperature reactors that gasify liquor through partial oxidation with either air or oxygen. The physical and chemical characteristics of both the gas and condensed phase were to be studied over the entire range of liquor conversion, and the rates and mechanisms of processes responsible for converting the liquor to its final smelt and syngas products were to be investigated. This would be accomplished by combining fundamental, lab-scale experiments with measurements taken using a new semi-pilot scale pressurized entrained-flow gasifier. As a result of insufficient availability of funds and changes in priority within the Office of Biomass Programs of the U.S. Department of Energy, the research program was terminated in its second year. In total, only half of the budgeted funding was made available for the program, and most of this was used during the first year for construction of the experimental systems to be used in the program. This had a severe impact on the program. As a consequence, most of the planned research was unable to be performed. Only studies that relied on computational modeling or existing experimental facilities started early enough to deliver useful results by the time to program was terminated Over the course of the program, small scale (approx. 1 ton/day) entrained-flow gasifier was designed and installed at the University of Utah's off-campus Industrial Combustion and Gasification Research Facility. The system is designed to operate at pressures as high as 32 atmospheres, and at temperatures as high as 1500 C (2730 F). Total blackliquor processing capacity under pressurized, oxygen-blown conditions should be in excess of 1 ton blackliquor solids per day. Many sampling ports along the conversion section of the system will allow detailed analysis of the environment in the gasifier under industrially representative conditions. Construction was mostly completed before the program was terminated, but resources were insufficient to operate the system. A system for characterizing blackliquor sprays in hot environments was designed and constructed. Silhouettes of blackliquor sprays formed by injection of blackliquor through a twin fluid (liquor and atomizing air) nozzle were videoed with a high-speed camera, and the resulting images were analyzed to identify overall characteristics of the spray and droplet formation mechanisms. The efficiency of liquor atomization was better when the liquor was injected through the center channel of the nozzle, with atomizing air being introduced in the annulus around the center channel, than when the liquor and air feed channels were reversed. Atomizing efficiency and spray angle increased with atomizing air pressure up to a point, beyond which additional atomizing air pressure had little effect. Analysis of the spray patterns indicates that two classifications of droplets are present, a finely dispersed 'mist' of very small droplets and much larger ligaments of liquor that form at the injector tip and form one or more relatively large droplets. This ligament and subsequent large droplet formation suggests that it will be challenging to obtain a narrow distribution of droplet sizes when using an injector of this design. A model for simulating liquor spray and droplet formation was developed by Simulent, Inc. of Toronto. The model was able to predict performance when spraying water that closely matched the vendor specifications. Simulation of liquor spray indicates that droplets on the order 200-300 microns can be expected, and that higher liquor flow will result in be

The objective of this project was to develop a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for blackliquor combustion based on continued laboratory fundamental studies. The project originated in October 1990 and was scheduled to run for four years. At that time, there was considerable emphasis on developing accurate predictions of the physical carryover of macroscopic particles of partially burnt blackliquor and smelt droplets out of the furnace, since this was seen as the main cause of boiler plugging. This placed a major emphasis on gas flow patterns within the furnace and on the mass loss rates and swelling and shrinking rates of burning blackliquor drops. As work proceeded on developing the recovery boiler furnace model, it became apparent that some recovery boilers encounter serious plugging problems even when physical carryover was minimal. After the original four-year period was completed, the project was extended to address this issue. The objective of the extended project was to improve the utility of the models by including the blackliquor chemistry relevant to air emissions predictions and aerosol formation, and by developing the knowledge base and computational tools to relate furnace model outputs to fouling and plugging of the convective sections of the boilers. The work done to date includes CFD model development and validation, acquisition of information on blackliquor combustion fundamentals and development of improved burning models, char bed model development, and model application and simplification.

This project developed and tested advanced Fourier transform infrared (FT-IR) instruments for process monitoring of blackliquor recovery boilers. The state-of-the-art FT-IR instruments successfully operated in the harsh environment of a blackliquor recovery boiler and provided a wealth of real-time process information. Concentrations of multiple gas species were simultaneously monitored in-situ across the combustion flow of the boiler and extractively at the stack. Sensitivity to changes of particulate fume and carryover levels in the process flow were also demonstrated. Boiler set-up and operation is a complex balance of conditions that influence the chemical and physical processes in the combustion flow. Operating parameters include blackliquor flow rate, liquor temperature, nozzle pressure, primary air, secondary air, tertiary air, boiler excess oxygen and others. The in-process information provided by the FT-IR monitors can be used as a boiler control tool since species indicative of combustion efficiency (carbon monoxide, methane) and pollutant emissions (sulfur dioxide, hydrochloric acid and fume) were monitored in real-time and observed to fluctuate as operating conditions were varied. A high priority need of the U.S. industrial boiler market is improved measurement and control technology. The sensor technology demonstrated in this project is applicable to the need of industry.

Experimental effort for the program to evaluate physical properties of kraft blackliquors is now proceeding well. Experimental work includes pulping, liquor analysis, lignin purification and characterization, vapor-liquid equilibria, heat capacity, heats of solution and combustion, and viscosity measurements. Measurement of thermal conductivity has not yet begun. Collection of the data necessary for development of generalized correlations is proceeding, but will require about two more years. The digester is operating very well. It is now possible to operate the digester as a closed, rotating reactor or as a batch reactor with liquor circulation. When operated with liquor circulation, temperatures within the chip bed can be monitored during cooking. Cooking is reproducible, and cooks are being performed to produce liquors for experimental studies. The digester could be further modified to permit us to conduct rapid exchange batch pulping or to permit us to simulate continuous pulping. Liquors to be used in experimental studies are concentrated in our large scale evaporator or in our small scale evaporator. The large scale evaporator is used to concentrate liquors to about 50% solids for storage and for use in studies requiring high solids liquors. The small scale evaporator is used for preparing final samples to as high as 85% solids and for measuring vapor-liquid equilibria. Liquors are now routinely analyzed to determine all components, except higher molecular weight organic acids and extractives. Lignin determination by uv-visible means has been improved. Lignin purification from blackliquor has been improved and lignin molecular weights are determined routinely. Work on lignin molecular weight distribution is still not satisfactory, but recent developments holds promise.

Blackliquor gasification provides the pulp and paper industry with a technology which could potentially replace recovery boilers with equipment that could reduce emissions and, if used in a combined cycle system, increase the power production of the mill allowing it to be a net exporter of electrical power. In addition, rather than burning the syngas produced in a gasifier, this syngas could be used to produce higher value chemicals or fuels. However, problems with structural materials such as the refractory lining of the reactor vessel have caused unplanned shutdowns and resulted in component replacement much sooner than originally planned. Through examination of exposed materials, laboratory corrosion tests and cooperative efforts with refractory manufacturers, many refractory materials issues in high-temperature blackliquor gasification have been addressed and optimized materials have been selected for this application. In this paper, an updated summary of the characterization and analysis techniques used for refractory screening and selection will be discussed along with characteristic results from these methods which have led to the selection of optimized materials for both the hot-face and back-up linings used in this application.

Blackliquor recovery boilers are an essential part of kraft mills. Their design and operating procedures have changed over time with the goal of providing improved boiler performance. These performance improvements are frequently associated with an increase in heat flux and/or operating temperature with a subsequent increase in the demand on structural materials associated with operation at higher temperatures and/or in more corrosive environments. Improvements in structural materials have therefore been required. In most cases the alternate materials have provided acceptable solutions. However, in some cases the alternate materials have solved the original problem but introduced new issues. This report addresses the performance of materials in the tubes forming primary air port openings and, particularly, the problems associated with use of stainless steel clad carbon steel tubes and the solutions that have been identified.

Steam gasification of carbon residue in bed solids of a low-temperature blackliquor gasifier was studied using a thermogravimetric system at 3 bar. Complete gasification of the carbon residue, which remained unreactive at 600 C, was achieved in about 10 min as the temperature increased to 800 C. The rate of gasification and its temperature dependence were evaluated from the non-isothermal experiment results. Effects of particle size and adding H{sub 2} and CO to the gasification agent were also studied. The rate of steam gasification could be taken as zero order in carbon until 80% of carbon was gasified, and for the rest of the gasification process the rate appeared to be first order in carbon. The maximum rate of carbon conversion was around 0.003/s and the activation energy was estimated to be in the range of 230-300 kJ/mol. The particle size did not show significant effect on the rate of gasification. Hydrogen and carbon monoxide appeared to retard the onset of the gasification process. (author)

In 2007, a change in the law regarding the alternative fuel mixture credit opened the door for paper mills to qualify a byproduct of paper manufacturing, blackliquor, as a fuel eligible for the credit. The credit is a refundable credit of $0.50 per gallon. Paper mills can produce hundreds of millions of gallons of blackliquor per year and qualified for the credit in 2009. In addition, in 2010 the IRS determined that these firms qualified for the cellulosic biofuels producer credit. Paper mill companies could amend their 2009 tax returns and swap their alternative fuel mixture credits for cellulosic biofuels producer credits worth $1.01 per gallon. The catch was that the alternative fuels mixture credit was refundable; the cellulosic biofuels producer credit was nonrefundable. This paper provides a series of mini cases exploring the tax planning, tax research, tax policy and financial statement implications of Packaging Corporation of America’s use of the alternative fuel mixture tax credit and subsequent amendment of its 2009 tax return in 2010 to swap its alternative fuel mixture tax credits for cellulosic biofuel producer credits. These cases may be directed for use in either upper-division undergraduate courses or graduate courses.

The goal of the program is to identify the optimal operating window for blackliquor gasification. The goals during this year are to prepare the PEFR for operation, conduct a series of preliminary screening tests to bracket BLG operating conditions, and develop a process model that can guide identification of the optimal operating window.

This project was initiated in October 1990, with the objective of developing and validating a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for blackliquor combustion based on continued laboratory fundamental studies. The key tasks to be accomplished were as follows: (1) Complete the development of enhanced furnace models that have the capability to accurately predict carryover, emissions behavior, dust concentrations, gas temperatures, and wall heat fluxes. (2) Validate the enhanced furnace models, so that users can have confidence in the predicted results. (3) Obtain fundamental information on aerosol formation, deposition, and hardening so as to develop the knowledge base needed to relate furnace model outputs to plugging and fouling in the convective sections of the boiler. (4) Facilitate the transfer of codes, black liquid submodels, and fundamental knowledge to the US kraft pulp industry. Volume 1 contains the main body of the report and the first 4 sections of Appendix 1: Modeling of blackliquor recovery boilers -- summary report; Flow and heat transfer modeling in the upper furnace of a kraft recovery boiler; Numerical simulation of blackliquor combustion; and Investigation of turbulence models and prediction of swirling flows for kraft recovery furnaces.

This paper describes a pilot scale high pressure entrained flow gasification experiment with spent cooking liquor from a sodium sulfite based delignification process in the DP-1 blackliquor gasifier in Piteå, Sweden. Approximately 92 tons of sulfite ...

...is a by-product of the corn wet-milling industry it would be insufficient...invention of much of the modern wet milling process, suggested corn steep liquor as a nutrient...general flowsheet of the corn wet-milling process; and to Dr. L...

The experimental work included 23 bench-scale tests in a 6-in.-diameter gasifier and two extended runs in a 33-in.-ID pilot-scale unit. The two pilot-scale runs included 26 test periods, each evaluated separately. The engineering analysis work consisted primarily of the correlation of test results and the development of a computer model describing the gasification process. 4 refs., 13 figs., 23 tabs.

Sample records for black liquor bark from the National Library of Energy Beta (NLEBeta)

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altitude Lodgepole Pine forests on the western and northern slopes of ColoradoColorado Â­ Initial countiesColorado Bark Beetle Cooperative Colorado Bark Beetle Cooperative A Place Based Collaborative of Land Management, National Park Service, Colorado State Forest Service, & Northwest Colorado Council

Recovering Soaps and Greases from Wool-Scouring liquors ... A NEW process, illustrated in the accompanying flowsheet, has been devised for recovering soaps and greases from waste wool-scouring liquors. ...

facilities (0.2 tph) focused on developing pressurized gasifiers. Their work is complemented by research at VIT (The Technical Research Centre of Finland) who have a 0.2 tph pressurized fluid bed test facility. The purpose of this paper is to describe...

Black spruce bark residues and primary sludges derived from the operation of the Daishowa pulp and paper plant in Quebec City, PQ, were processed by vacuum pyrolysis in a laboratory-scale batch reactor. The pyrolysis oil, water, charcoal, and gas were recovered and analyzed. The bark residues yielded 30.6% oil and 34.1% charcoal, and the primary sludges gave 40.1% oil and 30.1% charcoal on a feedstock air-dry basis. The oil phases recovered from the two pyrolysis experiments were fractionated into eight fractions; they were analyzed by gas chromatography/mass spectrometry. Both pyrolysis oil samples had a high content of phenolic compounds. These oils contained various fine chemicals that have possible commercial potential. Aliphatic and aromatic hydrocarbons, as well as long- and short-chain carboxylic acids, are also present in both pyrolysis oils.

(217) 352-7467. Excellent Mexican and Latin American- influenced food. Service can be a bit slowCHAMPAIGN-URBANA FOOD AND LIQUOR GUIDE 1. Introduction This is a short, incomplete, and personally. It is standard to tip 15-20% for reasonable service. A indicates a place that we like, and indicates a place we

A review of sulfur dioxide emission data for eight combination bark boilers in conjunction with the sulfur contents of the fuels reveals significant sulfur capture ranging from 10% to over 80% within the solid ash phase. Wood ash characteristics similar to activated carbon as well as the significant wood ash alkali oxide and carbonate fractions are believed responsible for the sulfur capture. Sulfur emissions from combination bark-fossil fuel firing are correlated to the sulfur input per ton of bark or wood residue fired.

Someshwar, A.V.; Jain, A.K. (National Council of the Paper Industry for Air and Stream Improvement, Gainesville, FL (United States))

AbstractEthnopharmacological relevance Marula (Sclerocarya birrea; family – Anacardiaceae) is an African plant, which enjoys wide socio-economic importance particularly in southern part of Africa. The fruits are consumed as food and also as alcoholic beverage (cream liquor). In different parts of Africa, the decoction of the bark is traditionally used for the treatment of dysentery, diarrhoea, and various other infectious conditions. The aim of the study was to investigate the anti-biofilm properties of the methanol extract of Marula bark (stem bark of Sclerocarya birrea), with a view towards combating the emergence of antimicrobial resistance often associated with bacterial biofilms. Materials and methods The standardized methanol extract was initially tested for its antimicrobial property. The crystal violet assay was used for evaluating anti-biofilm (biofilm formation by Pseudomonas aeuginosa) activity. Further in order to study the mechanism of anti-biofilm activity, the same was evaluated for understanding its role on various quorums sensing mediated phenomenon (swarming motility assay, protease and pyoverdin assay) that are known to be associated with the formation of biofilms and pathogenicity. Results The methanol extract showed no inhibition of bacterial growth up to a concentration of 200 µg/ml. Interestingly, the sample produced anti-biofilm activity (around 75% decrease; 100 µg/ml) at sub-lethal concentration. Further it also significantly reduced the QS mediated swarming motility. The release of various virulent factors (protease and pyoverdin) was found to be lowered when pre-treated with the extract. Conclusion The present study illustrates the anti-biofilm property Sclerocarya birrea. The standardized extract significantly disrupted the quorum sensing mediated production of biofilm formation and also inhibited swarming ability of the cells. The extract displayed a regulatory role on the secretion of protease and pyoverdin, two QS dependent pathogenic factors found in Pseudomonas aeruginosa. This study also validates the ethnobotanical use of Marula.

The present invention is a rapid method of determining the concentration of the major components in a chemical stream. The present invention is also a simple, low cost, device of determining the in-situ concentration of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously determining the concentrations of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples. The inventive method can be used in Kraft pulping operations to control white liquor causticizing efficiency, sulfate reduction efficiency in green liquor, oxidation efficiency for oxidized white liquor and the active and effective alkali charge to kraft pulping operations.

Evaluation of tree canopy epiphytes and bark characteristics associated with the presence myxomycetes were previously studied in the tree canopy, and observations suggested that species occurrence and with bark characteris- tics, such as water absorption, bark thickness, and bark pH. Study sites were located

Protein crystals were vitrified using high-pressure freezing in their mother liquor at 210 MPa and 77 K without cryoprotectants or oil coating. The method was successfully applied to photosystem II, which is representative of a membrane protein with a large unit cell and weak crystal contacts.

Regeneration of the Fe{sup II}-EDTA scrubbing liquors for simultaneous removal of SO{sub 2} and NO{sub x} in flue gas involves removing the nitrogen-sulfur (N-S) compounds accumulated in the liquor. In this paper, the authors investigated a simple regeneration process which selectively precipitates the N-S compounds as potassium salts and then hydrolyzes them to yield ammonium/potassium sulfate as a marketable byproduct. They believe this is the first report on precipitation and hydrolysis characteristics of the N-S compounds in actual waste scrubbing liquor. Precipitation of the N-S compounds was achieved by adding K{sub 2}SO{sub 4} to the scrubbing liquor. Effects of the amount of added K{sub 2}SO{sub 4} on the amount of removed N-S compounds, precipitated crystals, and the potassium left over in the scrubbing liquor were studied. Hydrolysis of the precipitated N-S compounds to ammonium sulfate was performed in a sulfuric acid environment. Effects of acidity, concentration of N-S compounds, and temperature on the hydrolysis are discussed. Analysis of the observed hydrolysis pattern showed that the reaction proceeded following first order kinetics in terms of N-S compound concentration.

Sample records for black liquor bark from the National Library of Energy Beta (NLEBeta)

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The Current design of liquor-combustion boilers is reviewed, along with options for lowering exhaust-gas emissions, particularly NOx. In many cases, modern boilers are being operated at or near optimal conditions for minimum NOx emissions. Possible upgrades to further reduce NOx emissions include addition of a selective noncatalytic reduction step, design modifications to lower the sectional load, a flue-gas recirculation system, and air staging. Calculated and experimental results show that these applications can lower NOx emissions by 40% or more.

Hydrolysis of Nitrogen-Sulfur Containing Compounds (N-SCC) derived from desulfurization liquors was carried out at high temperature and pressure with varying sulfuric acid concentration in order to determine the influence of temperature and acid concentration on time required for complete hydrolysis. An ammonia specific electrode (gas sensing) was used to monitor the concentration of ammonium ion in the hydrolyzed liquor. The results indicated a large shortening of time for complete hydrolysis of the Ca salt of N-SCC but varying acid concentration did influence the rate of hydrolysis. Since the physical-chemical analysis of the N-SCC obtained by re-liming the waste scrubbing liquor (containing the Fe-EDTA complex) was found to contain a high quantity of sodium, the N-SCC is believed to be a double salt of calcium and sodium. The final product, (NH{sub 4}){sub 2}SO{sub 4}, was obtained in experimentation using an evaporative crystallizer. The clean hydrolyzed liquor was neutralized with a strong NH{sub 2} solution before the final crystallization of (NH{sub 4}){sub 2}SO{sub 4}.

This paper reports on the reductive burning of high-yield spent pulping liquors which can be accomplished by the addition of pulverized coal to increase the heat content and generate the proper reducing conditions. Samples from a 78%-yield sodium bisulfite pulping process employing a hardwood furnish were mixed with 10-50% pulveriized coal and burned at 950[degrees]C under reducing conditions in a box furnace. Even in these uncontrolled combustion conditions 76. 5% of the sulfur found in the soluble portion of the smelt was converted from lignousulfonates to useful sulfide ion. For the remainder of the sulfur, analyses determined it to be 19. 5% as sulfite ion, 3. 1% as thiosulfate ion, and 0.9% as sulfate ion.

Influence of bark pH on the occurrence and distribution of tree canopy myxomycete species Sydney E species and bark pH but showed no difference with respect to height in the canopy. On individual trees in the canopy of living trees and neighboring grapevines. Corticolous myxomycetes of three temperate forests

Back to the Basics of Sustainability -- Houses of Bark and Energy Back to the Basics of Sustainability -- Houses of Bark and Energy of Sunshine Back to the Basics of Sustainability -- Houses of Bark and Energy of Sunshine August 2, 2012 - 2:23pm Addthis With new pipes and controls, the natural gas kilns Highland Craftsmen uses to produce poplar bark shingles will operate about 40 percent more efficiently, saving the company $5,000 a year in energy costs. | Photo courtesy of Highland Craftsmen. With new pipes and controls, the natural gas kilns Highland Craftsmen uses to produce poplar bark shingles will operate about 40 percent more efficiently, saving the company $5,000 a year in energy costs. | Photo courtesy of Highland Craftsmen. Julie McAlpin Communications Liaison, State Energy Program What are the key facts? With funds from the State Energy Program, Highland Craftsmen

This document is the final report for Cooperative Agreement DE-FC26-04NT42314, 'Kinetics Study of Mercury Reactions in FGD Liquors'. The project was co-funded by the U.S. DOE National Energy Technology Laboratory and EPRI. The objective of the project has been to determine the mechanisms and kinetics of the aqueous reactions of mercury absorbed by wet flue gas desulfurization (FGD) systems, and develop a kinetics model to predict mercury reactions in wet FGD systems. The model may be used to determine optimum wet FGD design and operating conditions to maximize mercury capture in wet FGD systems. Initially, a series of bench-top, liquid-phase reactor tests were conducted and mercury species concentrations were measured by UV/visible light spectroscopy to determine reactant and byproduct concentrations over time. Other measurement methods, such as atomic absorption, were used to measure concentrations of vapor-phase elemental mercury, that cannot be measured by UV/visible light spectroscopy. Next, a series of bench-scale wet FGD simulation tests were conducted. Because of the significant effects of sulfite concentration on mercury re-emission rates, new methods were developed for operating and controlling the bench-scale FGD experiments. Approximately 140 bench-scale wet FGD tests were conducted and several unusual and pertinent effects of process chemistry on mercury re-emissions were identified and characterized. These data have been used to develop an empirically adjusted, theoretically based kinetics model to predict mercury species reactions in wet FGD systems. The model has been verified in tests conducted with the bench-scale wet FGD system, where both gas-phase and liquid-phase mercury concentrations were measured to determine if the model accurately predicts the tendency for mercury re-emissions. This report presents and discusses results from the initial laboratory kinetics measurements, the bench-scale wet FGD tests, and the kinetics modeling efforts.

Four residues generated in a Kraft, pulp and paper plant, were characterized by X-ray fluorescence spectroscopy (XFA), powder X-ray diffraction (XRD), thermogravimmetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). A quantitative phase composition model, that accounts for the observed data and for the physico-chemical conditions of formation, was postulated for each material. Emphasis was given on the identification of the mineral components of each material. The green liquor dregs and the lime mud contain Calcite and Gipsite. The slaker grits contains Calcite, Portlandite, Pirssonite, Larnite and Brucite. The Calcite phase, present in the dregs and in the lime mud, has small amounts of magnesium replacing calcium. The wood ash contains Quartz as the major crystalline mineral phase.

During this quarterly period, an experimental investigation was performed to study the precipitation kinetics and hydrolysis characteristics of calcium imido disulfonate crystals (CaADS). The CaADS crystals were precipitated by a metathetical reaction of lime, supplied by Dravo Lime Co., with flue gas desulfurization (FGD) scrubber waste liquor. Before approaching for the continuous Double Draw-Off (DDO) crystallization studies, the influence of a Dravo lime slurry on the precipitation characteristics of N-S compounds will be established. A series of N-S compound batch crystallization studies were completed in a wide range of pH (7.0--9.0), and the influence of pH on the amount of lime required, as well as the amount of precipitate obtained, was investigated. Although the amount of precipitate increased with increase in solution pH, the safe or optimum pH for the precipitation of CaADS lies in the vicinity of 8.2 to 8.3. For studying the crystallization characteristics of CaADS crystals, a bench scale 7.0 liter DDO crystallizer was built. DDO crystallizer is found to be superior compared to Mixed Suspension Mixed Product Removal (MSMPR) crystallizer. The precipitated crystals were analyzed for elemental composition by chemical analysis. The crystals were also examined under optical microscope for their morphological features. The present studies confirmed our prediction that N-S compounds in the waste liquor can be precipitated by a reaction with lime slurry. The precipitated crystals were mostly calcium imido disulfonate.

between bark beetles and wildfire, the two most influential natural disturbance agents in these forests. Are the beetles setting the stage for larger, more severe wildfires? And are fires bringing on beetle epidemics and wildfire. Finally, climate change complicates understanding of wildfire and beetle epidemics, both of which

Highland Craftsmen Inc., a small poplar bark shingle manufacturer in North Carolina, recently achieved the incredible energy efficiency milestone of net zero electricity use with funds provided through the Energy Department’s State Energy Program (SEP) under the American Recovery and Reinvestment Act (Recovery Act). Learn more.

Sample records for black liquor bark from the National Library of Energy Beta (NLEBeta)

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Bark beetle outbreaks have killed billions of trees and affected millions of hectares of forest during recent decades. Our objective was to quantify responses of surface energy and hydrologic fluxes 2-3 years following a spruce beetle outbreak ...

The objective of this study is to evaluate the use of emulsified heavy oils to conduct the FCC reaction. The emulsified heavy oil was prepared by homogenizing. Properties of emulsified heavy oil, including int...

This study is an integral part of a project which aims at creating an economic process that can utilize cheap forestry residues such as twigs, cones, treetops, branches, and bark to produce renewable chemicals and liquid fuels. ... Further instruments were used for various analyses: furfural and hydroxymethylfurfural by HPLC (Dionex UltiMate 3000 equipped with diode array detector); acetic acid, formic acid, and ethanol by an HP 1100 HPLC; aldonic acids by HPAEC equipped with a Dionex CarboPac PA10 column; uronic acids by methanolysis/GC-FID (Shimadzu GC-2010 Plus with NB-30 capillary column of 30 m length and 0.32 mm interior diameter) according to Sundberg et al.(17) and Iakovlev and van Heiningen;(2) concentrations of sulfate and sulfite anions (after adding NaOH) by ion chromatography (Dionex ICS 1500, Sunnyvale, CA, USA); inorganic analysis of the feedstocks by a Varian Liberty ICP-AAS; CHN/S analysis of the feedstocks by a 2400 Series II CHN/S PerkinElmer elemental analyzer (Jones factor of 6.25 used to convert nitrogen content to protein content according to Mariotti et al.(18)); sulfur content in the LCC by combustion in oxygen in a Schöniger flask, followed by absorption of SO2 in H2O2 solution, and the formed sulfate anions were determined by ion chromatography (SCAN-CM 57:99). ...

The mass of a black hole has traditionally been identified with its energy. We describe a new perspective on black hole thermodynamics, one that identifies the mass of a black hole with chemical enthalpy, and the cosmological constant as thermodynamic pressure. This leads to an understanding of black holes from the viewpoint of chemistry, in terms of concepts such as Van der Waals fluids, reentrant phase transitions, and triple points. Both charged and rotating black holes exhibit novel chemical-type phase behaviour, hitherto unseen.

Black Holes at RHIC? Black Holes at RHIC? Further discussion by Physicist Dmitri Kharzeev on why RHIC cannot produce a real gravitational black hole Black holes are among the most mysterious objects in the universe. The gravitational field of a black hole is so strong that Einstein's general relativity tells us that nothing, not even light, can escape from the black hole's interior. However, in 1974 physicist Stephen Hawking demonstrated that black holes must emit radiation once the quantum effects are included. According to quantum mechanics, the physical vacuum is bubbling with short-lived virtual particle-antiparticle pairs. Creation of a particle-antiparticle pair from the vacuum conflicts with energy conservation, but energy need not be conserved at short times in quantum mechanics, according to Heisenberg's

The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness of the black hole horizon, (ii) by using standard black hole thermodynamics we show that accelerated black holes have a higher Hawking temperature than Unruh temperature of the accelerated frame, and (iii) the usual upper bound on the product of the mass and acceleration parameters (<1/27) is just a coordinate artifact. The main results are extended to accelerated rotating black holes with no significant changes.

We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. Such limits exist for both types of solutions; for the bi-rings it is obtained when the two rings drag each other to extremality through the effect of gravitational frame-dragging. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

We present detailed physics analyses of two different 4+1-dimensional asymptotically flat vacuum black hole solutions with spin in two independent planes: the doubly spinning black ring and the bicycling black ring system ("bi-rings"). The latter is a new solution describing two concentric orthogonal rotating black rings which we construct using the inverse scattering technique. We focus particularly on extremal zero-temperature limits of the solutions. We construct the phase diagram of currently known zero-temperature vacuum black hole solutions with a single event horizon, and discuss the non-uniqueness introduced by more exotic black hole configurations such as bi-rings and multi-ring saturns.

Black History Month is an annual celebration of achievements by black Americans and a time for recognizing the central role of African Americans in U.S. history. The event grew out of “Negro History Week,” created by historian Carter G. Woodson and other prominent African Americans. Other countries around the world, including Canada and the United Kingdom, also devote a month to celebrating black history.

I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these interactions. Larger global magnetohydrodynamic simulations as well as simulations incorporating plasma microphysics and full radiation hydrodynamics will be needed to unravel some of the current mysteries of black hole accretion.

A black hole of given mass, angular momentum, and charge can have a large number of different unobservable internal configurations which reflect the possible different initial configurations of the matter which collapsed to produce the hole. The logarithm of this number can be regarded as the entropy of the black hole and is a measure of the amount of information about the initial state which was lost in the formation of the black hole. If one makes the hypothesis that the entropy is finite, one can deduce that the black holes must emit thermal radiation at some nonzero temperature. Conversely, the recently derived quantum-mechanical result that black holes do emit thermal radiation at temperature ??2? k c, where ? is the surface gravity, enables one to prove that the entropy is finite and is equal to c3A4 G?, where A is the surface area of the event horizon or boundary of the black hole. Because black holes have negative specific heat, they cannot be in stable thermal equilibrium except when the additional energy available is less than 1/4 the mass of the black hole. This means that the standard statistical-mechanical canonical ensemble cannot be applied when gravitational interactions are important. Black holes behave in a completely random and time-symmetric way and are indistinguishable, for an external observer, from white holes. The irreversibility that appears in the classical limit is merely a statistical effect.

Web gigantism in Darwin's bark spider, a new species from Madagascar (Araneidae: Caerostris) Matjaz, is grossly underestimated. Most species build large webs at forest edges, clearings, and gardens niche: casting its web across streams, rivers and lakes, so that the orb is suspended above water

We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

Better computer models Better computer models High-tech tool predicts fire behavior in bark beetle-ravaged forests A high-tech computer model called HIGRAD/FIRETEC provides insights that are essential for front-line fire fighters. August 9, 2012 Researchers from LANL and the French Space Agency examine data from the Mars Science Laboratory Curiosity rover from inside the ChemCam Operations Center at NASA's Jet Propulsion Laboratory on Monday, Aug. 6, 2012, less than a day after the rover landed on Mars. The ChemCam team received signals indicating that the instrument is healthy and all systems are ready to go. During the Las Conchas fire of 2011, a Los Alamos resident watches the Jemez Mountains burn just a few miles west of town and near LANL. Contact Nancy Ambrosiano Communications Office

Field bioassays were conducted in south-central Alaska in a stand of Lutz spruce, Picea × lutzii, to determine whether a semiochemical interruptant (verbenone and trans-conophthorin) and/or a defense-inducing plant hormone (methyl jasmonate, MJ) could be used to protect individual standing trees from bark beetle attack. During two experiments (initiated in May 2004 and 2005, respectively), attacks by Ips perturbatus on standing trees were induced by using a three-component aggregation pheromone (ipsenol, cis-verbenol, and ipsdienol) and prevented by using the interruptant. In 2005, treatments from 2004 were repeated and additional treatments were evaluated by using MJ spray or injection with and without the interruptant. Aggregation began before 3 or 7 June, and attack density was monitored through 3 or 16 August. During both years, tree mortality caused by I. perturbatus was recorded twice (in August, and in May of the following year). In both experiments, attack density was greatest on trees baited with the three-component attractive pheromone, but was significantly reduced by addition of the semiochemical interruptant to trees baited with the attractant. There were no significant differences in attack density between attractant + interruptant-treated trees and unbaited trees. In 2004, mortality was highest among attractant-baited trees, whereas addition of the interruptant significantly reduced the level of initial (10 week post-treatment) and final (54 week post-treatment) mortality. In 2005, no significant reduction in attack density occurred on trees baited with the attractant when MJ was sprayed or injected. The highest initial (10.6 week post-treatment) and final (49.4 week post-treatment) mortality was observed among trees that had been injected with MJ and baited with the attractant. Mortality at the final assessment was significantly lower in all other treatment groups. As in 2004, addition of the interruptant to attractant-baited trees significantly reduced the level of final mortality compared to attractant-baited trees. MJ was not attractive or interruptive to I. perturbatus or associated bark beetles in a flight trapping study. However, MJ-treated trees (sprayed or injected) exuded copious amounts of resin on the bark surface. Anatomical analyses of felled trees from four treatment groups [Tween (solvent)-sprayed, MJ-sprayed, Tween-injected, and MJ-injected + attractant baited] showed that treatment with MJ increased the number and size of resin ducts produced following treatment. These analyses also revealed a reduction in radial growth in MJ-treated trees. Our results show that during both years, treatment with a simple, two-component interruptant system of verbenone and trans-conophthorin significantly reduced I. perturbatus attack density and tree mortality on attractant-baited trees and provided a full year of protection from bark beetle attack.

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Corn steep liquor (CSL) and fermented ammoniated condensed whey (FACW) were compared to cottonseed meal (CSM) as protein sources for wintering 61 lactating first-calf Hereford heifers and 32 yearling Hereford heifers on native range. Cattle were allotted by weight and individually fed 6 days per week for 12 weeks one of four protein treatments: negative control (NC), positive control (PC), CSL and FACW to provide .7, 1.5, .15 and 1.5 lb crude protein (CP) per day, respectively, to the lacating heifers and .2, .4, .4 and .4lb cP per day, respectively, to the yearling heifers. CMS was supplied in the CSL and FACW treatments at the same level as in the negative control. Lactating heifers fed the NC lost more (P less than .005) weight and body condition (120 lb and 1.6 units) than those fed the PC (45.8 lb and .9 units). Weight and condition losses were similar (P more than .05) for lactating heifers fed PC, CSL and FACW. Yearling heifers fed the NC lost more (P less than .005) weight than those fed the PC (49.4 vs 10.6 lb). Yearling heifers fed CSL and FACW gained more (P less than .005) weight than those fed the PC (17.6 and 9.3 vs - 10.6 lb). Feeding CSL resulted in signficantly lower rumen pH, lower ruminal acetate and higher ruminal butyrate, isovalerate and caproate levels than did feeding either control. Supplementing with FACW produced significantly lower rumen pH, higher rumen ammonia and soluble carbohydrate levels, lower ruminal acetate, and higher ruminal propionate and butyrate concentrations than did either control supplement. Corn steep liquor and FDCW appear to be effective protein sources for cows and heifers grazing winter native range.

Black Holes at RHIC? Black Holes at RHIC? Before RHIC began operations in 2000, some were concerned that it would produce black holes that would threaten the earth. Here's why those concerns were unfounded. Committee Review of Speculative "Disaster Scenarios" at RHIC In July 1999, Brookhaven Lab Director John Marburger convened a committee of distinguished physicists to write a comprehensive report on the arguments that address the safety of speculative disaster scenarios at RHIC. The scenarios are: Creation of a black hole that would "eat" ordinary matter. Initiation of a transition to a new, more stable universe. Formation of a "strangelet" that would convert ordinary matter to a new form. jaffee "We conclude that there are no credible mechanisms for catastrophic

Black Bear Black Bear Nature Bulletin No. 286-A December 9, 1967 Forest Preserve District of Cook County Richard B. Ogilvie, President Roland F. Eisenbeis, Supt. of Conservation THE BLACK BEAR The most amusing and human-like of all our American wild animals is the Black Bear. Slow, clumsy and loose-jointed in appearance, with a shambling gait, he can be very swift and nimble. Like any good clown he is also a good acrobat with a fine sense of balance and timing. He is a great climber in spite of his bulk. Shrewd and droll, he is very popular in menageries and as a performer in circuses and side shows because he learns tricks easily. He can stand on his hind legs to wrestle, box, dance, or beg for food and, occasionally, one becomes a graceful artist on roller skates. They love applause.

Two techniques for computing black hole entropy in generally covariant gravity theories including arbitrary higher derivative interactions are studied. The techniques are Wald's Noether charge approach introduced recently, and a field redefinition method developed in this paper. Wald's results are extended by establishing that his local geometric expression for the black hole entropy gives the same result when evaluated on an arbitrary cross-section of a Killing horizon (rather than just the bifurcation surface). Further, we show that his expression for the entropy is not affected by ambiguities which arise in the Noether construction. Using the Noether charge expression, the entropy is evaluated explicitly for black holes in a wide class of generally covariant theories. Further, it is shown that the Killing horizon and surface gravity of a stationary black hole metric are invariant under field redefinitions of the metric of the form $\\bar{g}_{ab}\\equiv g_{ab} + \\Delta_{ab}$, where $\\Delta_{ab}$ is a tensor field constructed out of stationary fields. Using this result, a technique is developed for evaluating the black hole entropy in a given theory in terms of that of another theory related by field redefinitions. Remarkably, it is established that certain perturbative, first order, results obtained with this method are in fact {\\it exact}. The possible significance of these results for the problem of finding the statistical origin of black hole entropy is discussed.}

The main objective of this program was to pilot the world's first commercial-scale production of an acceptable phenol formaldehyde (PF) resin containing natural resin (NR) ingredients, for use as an adhesive in Oriented-Strand Board (OSB) and plywood panel products. Natural Resin products, specifically MNRP are not lignin ''fillers''. They are chemically active, natural phenolics that effectively displace significant amounts of phenol in PF resins, and which are extracted from bark-derived and wood-derived bio-oils. Other objectives included the enhancement of the economics of NR (MNRP) production by optimizing the production of certain Rapid Thermal Processing (RTP{trademark}) byproducts, particularly char and activated carbon. The options were to activate the char for use in waste-water and/or stack gas purification. The preliminary results indicate that RTP{trademark} carbon may ultimately serve as a feedstock for activated carbon synthesis, as a fuel to be used within the wood product mill, or a fuel for an electrical power generating facility. Incorporation of the char as an industrial heat source for use in mill operations was L-P's initial intention for the carbon, and was also of interest to Weyerhaeuser as they stepped into in the project.

We argue that in the high energy QCD a true black disk wave function necessarily contains many quarks. This corresponds to necessity of non-vacuum reggeon loops in formation of a black disk. The result comes from decomposition of the black disk S-matrix in characters on group manifold.

We investigate the construction of black holes and black strings in vacuum plane wave spacetimes using the method of matched asymptotic expansions. We find solutions of the linearised equations of motion in the asymptotic region for a general source on a plane wave background. We observe that these solutions do not satisfy our previously defined conditions for being asymptotically plane wave. Hence, the space of asymptotically plane wave solutions is restricted. We consider the solution in the near region, treating the plane wave as a perturbation of a black object, and find that there is a regular black string solution but no regular black hole solution.

We follow the evolution of an asymptotically AdS black brane with a fixed temperature gradient at spatial infinity until a steady state is formed. The resulting energy density and energy flux of the steady state in the boundary theory are compared to a conjecture on the behavior of steady states in conformal field theories. Very good agreement is found.

... interior. These models reveal several significantly different behaviours. The simplest model, of a 'Schwarzschild' black hole, which possesses mass but no charge or angular momentum, has an ... into account, seal off the 'tunnel', and yield an interior similar to the Schwarzschild model, with an all-encompassing crushing singularity. More recently, there have been attempts6- ...

Supermassive black holes have generally been recognized as the most destructive force in nature. But in recent years, they have undergone a dramatic shift in paradigm. These objects may have been critical to the formation of structure in the early universe, spawning bursts of star formation and nucleating proto-galactic condensations. Possibly half of all the radiation produced after the Big Bang may be attributed to them, whose number is now known to exceed 300 million. The most accessible among them is situated at the Center of Our Galaxy. In the following pages, we will examine the evidence that has brought us to this point, and we will understand why many expect to actually image the event horizon of the Galaxy's central black hole within this decade.

High frequency dispersion does not alter the low frequency spectrum of Hawking radiation from a single black hole horizon, whether the dispersion entails subluminal or superluminal group velocities. We show here that in the presence of an inner horizon as well as an outer horizon the superluminal case differs dramatically however. The negative energy partners of Hawking quanta return to the outer horizon and stimulate more Hawking radiation if the field is bosonic or suppress it if the field is fermionic. This process leads to exponential growth or damping of the radiated flux and correlations among the quanta emitted at different times, unlike in the usual Hawking effect. These phenomena may be observable in condensed matter black hole analogues that exhibit “superluminal” dispersion.

A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

A group of seventh graders from Black Pine Circle school in Berkeley had the opportunity to experience the Advanced Light Source (ALS) as "users" via a collaborative field trip and proposal project. The project culminated with a field trip to the ALS for all seventh graders, which included a visit to the ALS data visualization room, a diffraction demonstration, a beamline tour, and informative sessions about x-rays and tomography presented by ALS scientists.

Advanced Algorithm Design Red-black Tree Jingjing Xia #12;Red-Black Tree A red-black tree is a binary search tree, and each node contains one extra field: its color, it can be either black or red of the binary search tree. If a binary search tree satisfies all the following red-black properties, it is a red

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Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

This dissertation covers two di erent but related topics: the construction of new black hole solutions and the study of the microscopic origin of black hole entropy. In the solution part, two di erent sets of new solutions are found. The rst...

... non-rotating black hole the particle can be lowered to no closer than 1.14 Schwarzschild radii, and the energy extracted can be no more than 63.2 per cent ... gram of matter-and the rope could be lowered no closer than 5 x 1011 Schwarzschild radii. This seems to rule out black holes as practical sources of energy. ...

We exhibit a static, cylindrically symmetric, exact solution to the Euler-Heisenberg field equations (EHFE) and prove that its effective geometry contains (optical) black holes. It is conjectured that there are also soliton solutions to the EHFE which contain black hole geometries.

A general formula for the entropy of stationary black holes in Lovelock gravity theories is obtained by integrating the first law of black hole mechanics, which is derived by Hamiltonian methods. The entropy is not simply one quarter of the surface area of the horizon, but also includes a sum of intrinsic curvature invariants integrated over a cross section of the horizon.

We investigate the geometry of four dimensional black hole solutions in the presence of stringy higher curvature corrections to the low energy effective action. For certain supersymmetric two charge black holes these corrections drastically alter the causal structure of the solution, converting seemingly pathological null singularities into timelike singularities hidden behind a finite area horizon. We establish, analytically and numerically, that the string-corrected two-charge black hole metric has the same Penrose diagram as the extremal four-charge black hole. The higher derivative terms lead to another dramatic effect -- the gravitational force exerted by a black hole on an inertial observer is no longer purely attractive! The magnitude of this effect is related to the size of the compactification manifold.

Black carbon snow albedo reduction Black carbon snow albedo reduction Title Black carbon snow albedo reduction Publication Type Journal Article Year of Publication 2012 Authors Hadley, Odelle L., and Thomas W. Kirchstetter Journal Nature Climate Change Volume 2 Pagination 437-440 Abstract Climate models indicate that the reduction of surface albedo caused by black-carbon contamination of snow contributes to global warming and near-worldwide melting of ice1, 2. In this study, we generated and characterized pure and black-carbon-laden snow in the laboratory and verified that black-carbon contamination appreciably reduces snow albedo at levels that have been found in natural settings1, 3, 4. Increasing the size of snow grains in our experiments decreased snow albedo and amplified the radiative perturbation of black carbon, which justifies the aging-related positive feedbacks that are included in climate models. Moreover, our data provide an extensive verification of the Snow, Ice and Aerosol Radiation model1, which will be included in the next assessment of the Intergovernmental Panel on Climate Change5.

Recent years have seen tremendous progress in the quest to detect supermassive black holes in the centers of nearby galaxies, and gas-dynamical measurements of the central masses of active galaxies have been valuable contributions to the local black hole census. This review summarizes measurement techniques and results from observations of spatially resolved gas disks in active galaxies, and reverberation mapping of the broad-line regions of Seyfert galaxies and quasars. Future prospects for the study of black hole masses in active galaxies, both locally and at high redshift, are discussed.

We apply the recently extended conserved Killing charge definition of Abbott-Deser-Tekin formalism to compute, for the first time, the energies of analytic Lifshitz black holes in higher dimensions. We then calculate the temperature and the entropy of this large family of solutions, and study and discuss the first law of black hole thermodynamics. Along the way we also identify the possible critical points of the relevant quadratic curvature gravity theories. Separately, we also apply the generalized Killing charge definition to compute the energy and the angular momentum of the warped AdS3 black hole solution of the three-dimensional new massive gravity theory.

ponderosa pine forests, and watershed management of the Black Hills. Keywords: Black Hills, silviculture of the Black Hills National Forest. The authors are grateful for the insightful and helpful reviews, and members of the Black Hills National Forest. We are thankful for Bob Hamre's editing of the manuscript

The physical process version and equilibrium state version of the first law of thermodynamics for a black object consisting of n-dimensional charged stationary axisymmetric black hole surrounded by a black rings, the so-called black Saturn, was derived. The general setting for our derivations is n-dimensional dilaton gravity with p+1 strength form fields.

The physical process version and equilibrium state version of the first law of thermodynamics for a black object consisting of n-dimensional charged stationary axisymmetric black hole surrounded by a black rings, the so-called black Saturn, was derived. The general setting for our derivations is n-dimensional dilaton gravity with p+1 strength form fields.

We investigate thermodynamics for a magnetically charged regular black hole (MCRBH), which comes from the action of general relativity and nonlinear electromagnetics, comparing with the Reissner-Norstr\\"om (RN) black hole in both four and two dimensions after dimensional reduction. We find that there is no thermodynamic difference between the regular and RN black holes for a fixed charge $Q$ in both dimensions. This means that the condition for either singularity or regularity at the origin of coordinate does not affect the thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$ thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim theory. We also identify the near-horizon entropy as the statistical entropy by using the AdS$_2$/CFT$_1$ correspondence.

About thirty years ago, Bekenstein and Hawking introduced three basic concepts relating to black hole, namely, the "area entropy", "gravitation temperature" and "thermal radiation". The author analyzes these concepts systematically and concludes that they are mostly inadequate or wrong. He points out that a black hole's taking in thermal radiation from the space is an energy-gathering process. It is special, even extraordinary. It reduces entropy, violating Clausius' second law.

We study the Hawking process on lattices falling into static black holes. The motivation is to understand how the outgoing modes and Hawking radiation can arise in a setting with a strict short distance cutoff in the free-fall frame. We employ two-dimensional free scalar field theory. For a falling lattice with a discrete time-translation symmetry we use analytical methods to establish that, for Killing frequency $\\omega$ and surface gravity $\\kappa$ satisfying $\\kappa\\ll\\omega^{1/3}\\ll 1$ in lattice units, the continuum Hawking spectrum is recovered. The low frequency outgoing modes arise from exotic ingoing modes with large proper wavevectors that "refract" off the horizon. In this model with time translation symmetry the proper lattice spacing goes to zero at spatial infinity. We also consider instead falling lattices whose proper lattice spacing is constant at infinity and therefore grows with time at any finite radius. This violation of time translation symmetry is visible only at wavelengths comparable to the lattice spacing, and it is responsible for transmuting ingoing high Killing frequency modes into low frequency outgoing modes.

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The effect of fuel composition on the fate of chlorine, sulfur, and potassium was investigated during an extensive measurement campaign in a 107 \\{MWth\\} bubbling fluidized bed (BFB) combustor. Bark, sludge, and solid recovered fuel (SRF) were co-combusted in different proportions during the campaign. The elemental composition of the fuel and outgoing ashes was determined, supplemented with gas composition measurements, to obtain the distribution of chlorine, sulfur, and potassium. Additionally, chemical fractionation was carried out for the pure fuels to study the leachability of the ash-forming elements. When firing bark and bark +sludge, potassium, sulfur, and chlorine ended up mainly in the fly ash stream. When SRF was a part of the fuel mixture a considerable amount of SO2 was measured in the second pass. Most of the chlorine entering with the fuel was found as gaseous \\{HCl\\} in the second pass, which indicates that sulfation reactions took place in the furnace. Most of the \\{HCl\\} and a part of the SO2 were captured in the baghouse filter ash and the emissions of these gases were low. This work showed the positive effects of co-firing challenging fuels.

Parikh-Wilczek tunnelling framework, which treats Hawking radiation as a tunnelling process, is investigated again. As the first order correction, the log-corrected entropy-area relation naturally emerges in the tunnelling picture if we consider the emission of a spherical shell. The second order correction of the emission rate for the Schwarzschild black hole is calculated too. In this level, the result is still in agreement with the unitary theory, however, the entropy of the black hole will contain three parts: the usual Bekenstein-Hawking entropy, the logarithmic term and the inverse area term. In our results the coefficient of the logarithmic term is -1. Apart from a coefficient, Our correction to the black hole entropy is consistent with that of loop quantum gravity.

We consider the issue of defining energy for test particles on a background black hole spacetime. We revisit the different notions of energy as defined by different observers. The existence of a time-like isometry allows for the notion of a total conserved energy to be well defined, and subsequently the notion of a gravitational potential energy is also meaningful. We then consider the situation in which the test particle is adsorbed by the black hole, and analyze the energetics in detail. In particular, we show that the notion of horizon energy es defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle's conserved energy. As another example, we comment a recent proposal to define energy of the black hole as seen by an observer at rest. This account is intended to be pedagogical and is aimed at the level of and as a complement to the standard textbooks on the subject.

Supermassive black holes from supermassive stars Supermassive black holes from supermassive stars 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues Â» submit Supermassive black holes from supermassive stars Supermassive stars in the early universe gave supermassive black holes a head start March 25, 2013 simulations suggest that star formation conditions back then allowed the first stars to become supermassive themselves In this simulation, a black hole that was just formed by the collapse of a supermassive star is surrounded by a distribution of gas (color indicates density). Because the black hole (located at the center but too small to see) grows by consuming the available gas, simulations like this one help determine how quickly the black hole can grow. The progenitor of this black

Gravitational waves emitted during the inspiral, plunge and merger of a black hole binary carry linear momentum. This results in an astrophysically important recoil to the final merged black hole, a “kick” that can eject ...

Extremal black holes tend to expel magnetic and electric fields. Fields are unable to reach the horizon because the length of the black hole throat blows up in the extremal limit. The length of the throat is related to the ...

The question of whether information is lost in black holes is investigated using Euclidean path integrals. The formation and evaporation of black holes is regarded as a scattering problem with all measurements being made at infinity. This seems to be well formulated only in asymptotically AdS spacetimes. The path integral over metrics with trivial topology is unitary and information preserving. On the other hand, the path integral over metrics with nontrivial topologies leads to correlation functions that decay to zero. Thus at late times only the unitary information preserving path integrals over trivial topologies will contribute. Elementary quantum gravity interactions do not lose information or quantum coherence.

We investigate isolated white holes surrounded by vacuum, which correspond to the time reversal of eternal black holes that do not evaporate. We show that isolated white holes produce quasi- thermal Hawking radiation. The time reversal of this radiation, incident on a black hole precursor, constitutes a special preparation that will cause the black hole to become eternal.

Conservation Assessment for Bloodroot in the Black Hills National Forest, South Dakota and Wyoming Forest Service Rocky Mountain Region Black Hills National Forest Custer, South Dakota April 2003 #12;Species Assessment of Bloodroot in the Black Hills National Forest, South Dakota and Wyoming J. Hope

We derive the absorption cross section of a minimally coupled scalar in the Lifshitz black hole obtained from the new massive gravity. The absorption cross section reduces to the horizon area in the low energy and massless limit of s-wave mode propagation, indicating that the Lifshitz black hole also satisfies the universality of low energy absorption cross section for black holes.

Signatures of black hole events at CERN's Large Hadron Collider are discussed. Event simulations are carried out with the Fortran Monte Carlo generator CATFISH. Inelasticity effects, exact field emissivities, color and charge conservation, corrections to semiclassical black hole evaporation, gravitational energy loss at formation and possibility of a black hole remnant are included in the analysis.

An exact solution of Einstein's equations which represents a pair of accelerating and rotating black holes (a generalised form of the spinning C-metric) is presented. The starting point is a form of the Plebanski-Demianski metric which, in addition to the usual parameters, explicitly includes parameters which describe the acceleration and angular velocity of the sources. This is transformed to a form which explicitly contains the known special cases for either rotating or accelerating black holes. Electromagnetic charges and a NUT parameter are included, the relation between the NUT parameter $l$ and the Plebanski-Demianski parameter $n$ is given, and the physical meaning of all parameters is clarified. The possibility of finding an accelerating NUT solution is also discussed.

In these two lectures, we will address the topic of the creation of small black holes during particle collisions in a ground-based accelerator, such as LHC, in the context of a higher-dimensional theory. We will cover the main assumptions, criteria and estimates for their creation, and we will discuss their properties after their formation. The most important observable effect associated with their creation is likely to be the emission of Hawking radiation during their evaporation process. After presenting the mathematical formalism for its study, we will review the current results for the emission of particles both on the brane and in the bulk. We will finish with a discussion of the methodology that will be used to study these spectra, and the observable signatures that will help us identify the black-hole events.

In this paper we revisit thermodynamic constraints on primordial black hole (PBH) formation in the early universe. Under the assumption that PBH mass is equal to the cosmological horizon mass, one can use the 2nd Law of Thermodynamics to put a lower limit on the PBH mass. In models of PBH formation, however, PBHs are created at some fraction of the horizon mass. We show that this thermodynamic constraint still holds for subhorizon PBH formation.

We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

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We present an overall picture of the advances in the description of black hole physics from the perspective of loop quantum gravity. After an introduction that discusses the main conceptual issues we present some details about the classical and quantum geometry of isolated horizons and their quantum geometry and then use this scheme to give a natural definition of the entropy of black holes. The entropy computations can be neatly expressed in the form of combinatorial problems solvable with the help of methods based on number theory and the use of generating functions. The recovery of the Bekenstein-Hawking law and corrections to it is explained in some detail. After this, due attention is paid to the discussion of semiclassical issues. An important point in this respect is the proper interpretation of the horizon area as the energy that should appear in the statistical-mechanical treatment of the black hole model presented here. The chapter ends with a comparison between the microscopic and semiclassical app...

The entanglement entropy is a fundamental quantity which characterizes the correlations between sub-systems in a larger quantum-mechanical system. For two sub-systems separated by a surface the entanglement entropy is proportional to the area of the surface and depends on the UV cutoff which regulates the short-distance correlations. The geometrical nature of the entanglement entropy calculation is particularly intriguing when applied to black holes when the entangling surface is the black hole horizon. I review a variety of aspects of this calculation: the useful mathematical tools such as the geometry of spaces with conical singularities and the heat kernel method, the UV divergences in the entropy and their renormalization, the logarithmic terms in the entanglement entropy in 4 and 6 dimensions and their relation to the conformal anomalies. The focus in the review is on the systematic use of the conical singularity method. The relations to other known approaches such as 't Hooft's brick wall model and the Euclidean path integral in the optical metric are discussed in detail. The puzzling behavior of the entanglement entropy due to fields which non-minimally couple to gravity is emphasized. The holographic description of the entanglement entropy of the black hole horizon is illustrated on the two- and four-dimensional examples. Finally, I examine the possibility to interpret the Bekenstein-Hawking entropy entirely as the entanglement entropy.

We examine the LHC phenomenology of quantum black holes in models of TeV gravity. By quantum black holes we mean black holes of the smallest masses and entropies, far from the semiclassical regime. These black holes are formed and decay over short distances, and typically carry SU(3) color charges inherited from their parton progenitors. Based on a few minimal assumptions, such as gauge invariance, we identify interesting signatures for quantum black hole decay such as 2 jets, jet + hard photon, jet + missing energy and jet + charged lepton, which should be readily visible above background. The detailed phenomenology depends heavily on whether one requires a Lorentz invariant, low-energy effective field theory description of black hole processes.

In this paper we consider magnetized black holes and black rings in the higher dimensional dilaton gravity. Our study is based on exact solutions generated by applying a Harrison transformation to known asymptotically flat black hole and black ring solutions in higher dimensional spacetimes. The explicit solutions include the magnetized version of the higher dimensional Schwarzschild-Tangherlini black holes, Myers-Perry black holes and five dimensional (dipole) black rings. The basic physical quantities of the magnetized objects are calculated. We also discuss some properties of the solutions and their thermodynamics. The ultrarelativistic limits of the magnetized solutions are briefly discussed and an explicit example is given for the $D$-dimensional magnetized Schwarzschild-Tangherlini black holes.

It has recently been pointed out that particles falling freely from rest at infinity outside a Kerr black hole can in principle collide with an arbitrarily high center of mass energy in the limiting case of maximal black hole spin. Here we aim to elucidate the mechanism for this fascinating result, and to point out its practical limitations, which imply that ultraenergetic collisions cannot occur near black holes in nature.

A trialogue. Ted, Don, and Carlo consider the nature of black hole entropy. Ted and Carlo support the idea that this entropy measures in some sense ``the number of black hole microstates that can communicate with the outside world.'' Don is critical of this approach, and discussion ensues, focusing on the question of whether the first law of black hole thermodynamics can be understood from a statistical mechanics point of view.

Bekenstein and Meisels used statistical thermodynamic arguments to obtain the probability distribution of fermions emitted by a black hole when a fermion is incident. In contrast with Bekenstein and Meisels, we model the black hole as a perfect blackbody surrounded by a mirror. Our probability distribution for emitted fermions agrees with the probability distribution of Bekenstein and Meisels, but the interpretation of how fermions interact with the black hole is different from the interpreteation given by Bekenstein and Meisels.

The behavior of a charged scalar field in the RN black hole space time is studied using WKB approximation. In the present work it is assumed that matter waves can get reflected from the event horizon. Using this effect, the Hawking temperature and the absorption cross section for RN black hole placed in a charged scalar field are calculated. The absorption cross section $\\sigma _{abs}$ is found to be inversely proportional to square of the Hawking temperature of the black hole.

809 CHAPTER 10 Red-black Trees Objectives Â· To know what a red-black tree is (Â§10.1). Â· To convert a red-black tree to a 2-4 tree and vice versa (Â§10.2). Â· To design the RBTree class that extends the BinaryTree class (Â§10.3). Â· To insert an element in a red-black tree and resolve the double red problem

Considering a generalized action for the Einstein-Maxwell theory in four dimensions coupled to scalar and pseudoscalar fields, the thermodynamic properties of asymptotically flat black hole solutions in such a background are investigated. Bekenstein-Hawking area-entropy law is verified for these class of black holes. From the property of specific heat, it is shown that such black holes can be stable for a certain choice of the parameters like charge, mass, and the scalar vacuum expectation value. The possibility of a black hole phase transition is discussed in this context.

This paper provides a brief review of the history of our understanding and knowledge of black holes. Starting with early speculations on ``dark stars'' I discuss the Schwarzschild "black hole" solution to Einstein's field equations and the development of its interpretation from "physically meaningless" to describing the perhaps most exotic and yet "most perfect" macroscopic object in the universe. I describe different astrophysical black hole populations and discuss some of their observational evidence. Finally I close by speculating about future observations of black holes with the new generation of gravitational wave detectors.

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We show that a central presumption in the debate over black-hole information loss is incorrect. Ensuring that information not escape during evaporation does not require that it all remain trapped until the final stage of the process. Using the recent quantum information-theoretic result of locking, we show that the amount of information that must remain can be very small, even as the amount already radiated is negligible. Information need not be additive: A small system can lock a large amount of information, making it inaccessible. Only if the set of initial states is restricted can information leak.

It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.

Recent developments in string theory have brought forth considerable interest in time-dependent hair on extended objects. This novel new hair is typically characterized by a wave profile along the horizon and angular momentum quantum numbers l,m in the transverse space. In this work, we present an extensive treatment of such oscillating black objects, focusing on their geometric properties. We first give a theorem of purely geometric nature, stating that such wavy hair cannot be detected by any scalar invariant built out of the curvature and/or matter fields. However, we show that the tidal forces detected by an infalling observer diverge at the {open_quotes}horizon{close_quotes} of a black string superposed with a vibration in any mode with l{ge}1. The same argument applied to longitudinal (l=0) waves detects only finite leading-order tidal forces. We also provide an example with a manifestly smooth metric, proving that at least a certain class of these longitudinal waves have regular horizons. {copyright} {ital 1997} {ital The American Physical Society}

We study the superradiant scattering of gravitational waves by a nearly extremal black hole (dimensionless spin $a=0.99$) by numerically solving the full Einstein field equations, thus including backreaction effects. This allows us to study the dynamics of the black hole as it loses energy and angular momentum during the scattering process. To explore the nonlinear phase of the interaction, we consider gravitational wave packets with initial energies up to $10%$ of the mass of the black hole. We find that as the incident wave energy increases, the amplification of the scattered waves, as well as the energy extraction efficiency from the black hole, is reduced. During the interaction the apparent horizon geometry undergoes sizable nonaxisymmetric oscillations. The largest amplitude excitations occur when the peak frequency of the incident wave packet is above where superradiance occurs, but close to the dominant quasinormal mode frequency of the black hole.

SSA-OBS) SSA-OBS) View an aerial photo-map of the SSA-OBS site. The 1.3 km road and boardwalk from OBS (facing North) The control box at the base of the flux tower The ARGO ATV used to haul equipment to OBS The double-scaffold flux tower The hut and boardwalk The TE canopy tower Construction during 1993 of the tower site at the Old Black Spruce (SSA-OBS) Trail into SSA-OBS. Large scar and canal created by construction vehicles cutting a new path each visit to avoid being mired in bog. Photograph of construction vehicle in action as it lays the electrical cable into SSA-OBS sites. Tower construction crew working on the foundation for the SSA-OBS tower. Aerial view of double-scaffold flux tower at SSA-OBS site and 100 m cable tramway for transporting the PARABOLA instrument between the flux and Rohn tower.

We calculate the quantum radiation power of black holes which are asymptotic to the Einstein-de Sitter universe at spatial and null infinities. We consider two limiting mass accretion scenarios, no accretion and significant accretion. We find that the radiation power strongly depends on not only the asymptotic condition but also the mass accretion scenario. For the no accretion case, we consider the Einstein-Straus solution, where a black hole of constant mass resides in the dust Friedmann universe. We find negative cosmological correction besides the expected redshift factor. This is given in terms of the cubic root of ratio in size of the black hole to the cosmological horizon, so that it is currently of order $10^{-5} (M/10^{6}M_{\\odot})^{1/3} (t/14 {Gyr})^{-1/3}$ but could have been significant at the formation epoch of primordial black holes. Due to the cosmological effects, this black hole has not settled down to an equilibrium state. This cosmological correction may be interpreted in an analogy with the radiation from a moving mirror in a flat spacetime. For the significant accretion case, we consider the Sultana-Dyer solution, where a black hole tends to increase its mass in proportion to the cosmological scale factor. In this model, we find that the radiation power is apparently the same as the Hawking radiation from the Schwarzschild black hole of which mass is that of the growing mass at each moment. Hence, the energy loss rate decreases and tends to vanish as time proceeds. Consequently, the energy loss due to evaporation is insignificant compared to huge mass accretion onto the black hole. Based on this model, we propose a definition of quasi-equilibrium temperature for general conformal stationary black holes.

model of black hole production and decay which can be interfaced to existing Monte Carlo programs using the Les Houches accord [4]. The major new theoretical input to the generator is the inclusion of the recently calculated ‘grey-body’ factors for black... ? TH geometric arguments show that ?l,m? ? (?rh)2 in any number of dimensions, which means that at high energies the shape of the spectrum is like that of a black body. However the low energy behaviour of the grey-body factors is spin-dependent and also...

We calculated the optical conductivity tensor of multilayers black phosphorus using the Kubo formula within an effective low-energy Hamiltonian. The optical absorption spectra of multilayers black phosphorus are shown to vary sensitively with thickness, doping, and light polarization. In conjunction with experimental spectra obtained from infrared absorption spectroscopy, we discuss the role of interband coupling and disorder on the observed anisotropic absorption spectra. Multilayers black phosphorus might offer attractive alternatives to narrow gap compound semiconductors for optoelectronics across mid- to near-infrared frequencies.

Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

We consider a macroscopic charge-current carrying (cosmic) string in the background of a Schwarzschild black hole. The string is taken to be circular and is allowed to oscillate and to propagate in the direction perpendicular to its plane (that is parallel to the equatorial plane of the black hole). Numerical investigations indicate that the system is non-integrable, but the interaction with the gravitational field of the black hole still gives rise to various qualitatively simple processes like `adiabatic capture' and `string transmutation'.

In this paper we study the thermodynamics and state space geometry of regular black hole solutions such as Bardeen black hole, Ay\\'{o}n-Beato and Garc\\'{i}a black hole, Hayward black hole and Berej-Matyjasek-Trynieki-Wornowicz black hole. We find that all these black holes show second order thermodynamic phase transitions(SOTPT) by observing discontinuities in heat capacity-entropy graphs as well as the cusp type double point in free energy-temperature graph. Using the formulation of geometrothermodynamics we again find the singularities in the heat capacity of the black holes by calculating the curvature scalar of the Legendre invariant metric.

We study the thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalizations. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization and does not favor the Bousso-Hawking normalization.

We study thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalizations. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization, and does not favor the Bousso-Hawking normalization.

We investigate the thermodynamics of the noncommutative black hole whose static picture is similar to that of the nonsingular black hole known as the de Sitter-Schwarzschild black hole. It turns out that the final remnant of extremal black hole is a thermodynamically stable object. We describe the evaporation process of this black hole by using the noncommutativity-corrected Vaidya metric. It is found that there exists a close relationship between thermodynamic approach and evaporation process.

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The strategy of enlightened bi-dialectalism used by the schools in the United States to deal with the problem of Black English is a significant attempt at social engineering. This attempt is motivated by basic linguistic ...

The Newman-Penrose constants of the spacetime corresponding to the development of the Brill-Lindquist initial data are calculated by making use of a particular representation of spatial infinity due to H. Friedrich. The Brill-Lindquist initial data set represents the head-on collision of two non-rotating black holes. In this case one non-zero constant is obtained. Its value is given in terms of the product of the individual masses of the black holes and the square of a distance parameter separating the two black holes. This constant retains its value all along null infinity, and therefore it provides information about the late time evolution of the collision process. In particular, it is argued that the magnitude of the constants provides information about the amount of residual radiation contained in the spacetime after the collision of the black holes.

Two central questions drive this research: (1) Are there trends in ethnic identification among blacks and whites; and (2) Are there meaningful differences between groups that identify differently? I use descriptive and regression analysis...

We consider weakly magnetized non-rotating black holes. In the presence of a regular magnetic field the motion of charged particles in the vicinity of a black hole is modified. As a result, the position of the innermost stable circular orbit (ISCO) becomes closer to the horizon. When the Lorentz force is repulsive (directed from the black hole) the ISCO radius can reach the gravitational radius. In the process of accretion charged particles (ions) of the accreting matter can be accumulated near their ISCO, while neutral particles fall down to the black hole after they reach $6M$ radius. The sharp spectral line Fe K$\\alpha$, emitted by iron ions at such orbits, is broadened when the emission is registered by a distant observer. In this paper we study this broadening effect and discuss how one can extract information concerning the strength of the magnetic field from the observed spectrum.

We review various properties of the exceptional Euclidean Jordan algebra of degree three. Euclidean Jordan algebras of degree three and their corresponding Freudenthal triple systems were recently shown to be intimately related to extremal black holes in N=2, d=4 homogeneous supergravities. Using a novel type of eigenvalue problem with eigenmatrix solutions, we elucidate the rich matrix geometry underlying the exceptional N=2, d=4 homogeneous supergravity and explore the relations to extremal black holes.

THE STRUCTURE OF THE CARBON BLACK FLAME A Dissertation By W1 111 ami Kermit Anderson THEHSR UCOF Approval as to style and content recommended Head of tiie Department of Chemistry A Dissertation Submitted to the Faculty of the Agricultural... and Mechanical College of. Texas in Parti ail Fulfilment of the Requirements for the Degree of Doctor of Philosophy THE STRUCTURE OF THE CARBON BLACK FLAME Major Subject: Chemistry AB William Hermit Anderson:\\ t * August 1945 THE STRUCTURE OF THE. CARBON...

A general formula for the entropy of stationary black holes in Lovelock higher-curvature gravity theories is obtained by integrating the first law of black hole mechanics, which is derived by Hamiltonian methods. The entropy is not simply one quarter of the surface area of the horizon, but also includes a sum of intrinsic curvature invariants integrated over a cross section of the horizon.

We show that the electromagnetic excitations of the Kerr black hole have very strong back reaction on metric. In particular, the electromagnetic excitations aligned with the Kerr congruence form the light-like beams which overcome horizon, forming the holes in it, which allows matter to escape interior. So, there is no information lost inside the black hole. This effect is based exclusively on the analyticity of the algebraically special solutions.

We discuss the initial value problem of general relativity in its recently unified Lagrangian and Hamiltonian pictures and present a multi-domain pseudo-spectral collocation method to solve the resulting coupled nonlinear partial differential equations. Using this code, we explore several approaches to construct initial data sets containing one or two black holes: We compute quasi-circular orbits for spinning equal mass black holes and unequal mass (nonspinning) black holes using the effective potential method with Bowen-York extrinsic curvature. We compare initial data sets resulting from different decompositions, and from different choices of the conformal metric with each other. Furthermore, we use the quasi-equilibrium method to construct initial data for single black holes and for binary black holes in quasi-circular orbits. We investigate these binary black hole data sets and examine the limits of large mass-ratio and wide separation. Finally, we propose a new method for constructing spacetimes with superposed gravitational waves of possibly very large amplitude.

We calculate the quantum radiation power of black holes which are asymptotic to the Einstein-de Sitter universe at spatial and null infinities. We consider two limiting mass accretion scenarios, no accretion and significant accretion. We find that the radiation power strongly depends on not only the asymptotic condition but also the mass accretion scenario. For the no accretion case, we consider the Einstein-Straus solution, where a black hole of constant mass resides in the dust Friedmann universe. We find negative cosmological correction besides the expected redshift factor. This is given in terms of the cubic root of ratio in size of the black hole to the cosmological horizon, so that it is currently of order $10^{-5} (M/10^{6}M_{\\odot})^{1/3} (t/14 {Gyr})^{-1/3}$ but could have been significant at the formation epoch of primordial black holes. Due to the cosmological effects, this black hole has not settled down to an equilibrium state. This cosmological correction may be interpreted in an analogy with th...

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Constellation-X is a premiere X-ray spectroscopy mission due to launch within the next decade. With a factor of 100 increase in sensitivity over current X-ray spectroscopy missions and an excellent energy resolution of 2 eV at 6 keV one of the prime science goals of the mission will be to observe activity near the black hole event horizon by measuring changes in the Fe K? fluorescence emission line profile and time-linked intensity changes between the line and the continuum. Detailed variability studies with Constellation-X will allow us to reconstruct “images” of the accretion disk probe the effects of strong gravity in the vicinity of black holes and measure black hole mass and spin via deconvolution of the line profile.

We calculate the required energy for duplication of information in the context of black hole complementarity in the rainbow Schwarzschild black hole. The resultant energy can be written as the well-defined limit given by the conventional result for the vanishing rainbow parameter which characterizes the deformation of the relativistic dispersion relation in the freely falling frame. It shows that the duplication of information in quantum mechanics could be not allowed below a certain critical value of the rainbow parameter; however, it could be possible above the critical value of the rainbow parameter, so that the consistent formulation in the rainbow Schwarzschild black hole requires additional constraints or any other resolutions for the latter case.

Non-perturbative quantum corrections to supersymmetric black hole entropy often involve nontrivial number-theoretic phases called Kloosterman sums. We show how these sums can be obtained naturally from the functional integral of supergravity in asymptotically AdS_2 space for a class of black holes. They are essentially topological in origin and correspond to charge-dependent phases arising from the various gauge and gravitational Chern-Simons terms and boundary Wilson lines evaluated on Dehn-filled solid 2-torus. These corrections are essential to obtain an integer from supergravity in agreement with the quantum degeneracies, and reveal an intriguing connection between topology, number theory, and quantum gravity. We give an assessment of the current understanding of quantum entropy of black holes.

The AGN Black Hole Mass Database is a compilation of all published spectroscopic reverberation-mapping studies of active galaxies. We have created a public web interface, where users may get the most up-to-date black hole masses from reverberation mapping for any particular active galactic nucleus (AGN), as well as obtain the individual measurements upon which the masses are based and the appropriate references. While the database currently focuses on the measurements necessary for black hole mass determinations, we also plan to expand it in the future to include additional useful information, such as host-galaxy characteristics. New reverberation mapping results will also be incorporated into the database as they are published in peer-refereed journals.

We investigate the thermodynamics of Lovelock-Lifshitz black branes. We begin by introducing the finite action of third order Lovelock gravity in the presence of a massive vector field for a flat boundary, and use it to compute the energy density of these black branes. Using the field equations, we find a conserved quantity along the r coordinate that relates the metric parameters at the horizon and at infinity. Remarkably, though the subleading large-r behavior of Lovelock-Lifshitz black branes differs substantively from their Einsteinian Lifshitz counterparts, we find that the relationship between the energy density, temperature, and entropy density is unchanged from Einsteinian gravity. Using the first law of thermodynamics to obtain the relationship between entropy and temperature, we find that it too is the same as the Einsteinian case, apart from a constant of integration that depends on the Lovelock coefficients.

If the scale of quantum gravity is near a TeV, black holes will be copiously produced at the CERN LHC. In this work we study the main properties of the light descendants of these black holes. We show that the emitted partons are closely spaced outside the horizon, and hence they do not fragment into hadrons in vacuum but more likely into a kind of quark-gluon plasma. Consequently, the thermal emission occurs far from the horizon, at a temperature characteristic of the QCD scale. We analyze the energy spectrum of the particles emerging from the “chromosphere,” and find that the hard hadronic jets are almost entirely suppressed. They are replaced by an isotropic distribution of soft photons and hadrons, with hundreds of particles in the GeV range. This provides a new distinctive signature for black hole events at LHC.

Taking the extremal limit of a non-extremal Reissner-Nordstr\\"om black hole (by externally varying the mass or charge), the region between the inner and outer event horizons experiences an interesting fate -- while this region is absent in the extremal case, it does not disappear in the extremal limit but rather approaches a patch of $AdS_2\\times S^2$. In other words, the approach to extremality is not continuous, as the non-extremal Reissner-Nordstr\\"om solution splits into two spacetimes at extremality: an extremal black hole and a disconnected $AdS$ space. We suggest that the unusual nature of this limit may help in understanding the entropy of extremal black holes.

Supersymmetric closed string theories contain an infinite tower of BPS-saturated, oscillating, macroscopic strings in the perturbative spectrum. When these theories have dual formulations, this tower of states must exist nonperturbatively as solitons in the dual theories. We present a general class of exact solutions of low-energy supergravity that corresponds to all these states. After dimensional reduction they can be interpreted as supersymmetric black holes with a degeneracy related to the degeneracy of the string states. For example, in four dimensions we obtain a point-like solution which is asymptotic to a stationary, rotating, electrically-charged black hole with Regge-bounded angular momentum and with the usual ring-singularity replaced by a string source. This further supports the idea that the entropy of supersymmetric black holes can be understood in terms of counting of string states. We also discuss some applications of these solutions to string duality.

Cool thermal emission components have recently been revealed in the X-ray spectra of a small number of ultra-luminous X-ray (ULX) sources with L_X > 1 E+40 erg/s in nearby galaxies. These components can be well fitted with accretion disk models, with temperatures approximately 5-10 times lower than disk temperatures measured in stellar-mass Galactic black holes when observed in their brightest states. Because disk temperature is expected to fall with increasing black hole mass, and because the X-ray luminosity of these sources exceeds the Eddington limit for 10 Msun black holes (L_Edd = 1.3 E+39 erg/s), these sources are extremely promising intermediate-mass black hole candidates (IMBHCs). In this Letter, we directly compare the inferred disk temperatures and luminosities of these ULXs, with the disk temperatures and luminosities of a number of Galactic black holes. The sample of stellar-mass black holes was selected to include different orbital periods, companion types, inclinations, and column densities. These ULXs and stellar-mass black holes occupy distinct regions of a L_X -- kT diagram, suggesting these ULXs may harbor IMBHs. We briefly discuss the important strengths and weaknesses of this interpretation.

We investigate the topology of Schwarzschild's black hole through the immersion of this space-time in spaces of higher dimension. Through the immersions of Kasner and Fronsdal we calculate the extension of the Schwarzschild's black hole.

Radiating black holes pose a number of puzzles for semiclassical and quantum gravity. These include the transplanckian problem -- the nearly infinite energies of Hawking particles created near the horizon, and the final state of evaporation. A definitive resolution of these questions likely requires robust inputs from quantum gravity. We argue that one such input is a quantum bound on curvature. We show how this leads to an upper limit on the redshift of a Hawking emitted particle, to a maximum temperature for a black hole, and to the prediction of a Planck scale remnant.

CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.

We discuss some recent results on black hole thermodynamics within the context of effective gravitational actions including higher-curvature interactions. Wald's derivation of the First Law demonstrates that black hole entropy can always be expressed as a local geometric density integrated over a space-like cross-section of the horizon. In certain cases, it can also be shown that these entropy expressions satisfy a Second Law. One such simple example is considered from the class of higher curvature theories where the Lagrangian consists of a polynomial in the Ricci scalar.

We first show that stationary black holes satisfy an extremely simple quasilocal form of the first law, ?E=?¯8??A, where the (quasilocal) energy E=A/(8??) and (local) surface gravity ?¯=1/?, with A the horizon area and ? is a proper length characterizing the distance to the horizon of a preferred family of quasilocal observers suitable for thermodynamical considerations. Our construction is extended to the more general framework of isolated horizons. The local surface gravity is universal. This has important implications for semiclassical considerations of black hole physics as well as for the fundamental quantum description arising in the context of loop quantum gravity.

We propose a combination of two mechanisms that can resolve the black hole information paradox. The first process is that the black hole shrinks by a first order transition, since we assume the entropy is discontinuous. The black hole disappears. The second type of processes conserves unitarity. We assume that within the black hole micro-reversible quantum mechanical processes take place. These are ordinary particle processes, e.g. the decay of an electron and a positron into two photons.

In this paper we have discussed geodesics and the motion of test particle in the gravitational field of noncommutative charged black hole spacetime. The motion of massive and massless particle have been discussed seperately. A comparative study of noncommutative charged black hole and usual Reissner-Nordstrom black hole has been done. The study of effective potential has also been included. Finally, we have examined the scattering of scalar waves in noncommutative charged black hole spacetime.

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......mass-accretion-rate variation per binary...because each black hole passes across the circumbinary...mass-accretion-rate variation per binary...holes|black hole physics|Galaxies: nuclei...because each black hole passes across the circumbinary...the mass accretion rates is also independent......

We study quantum tunneling of scalar particles from black strings. For this purpose we apply WKB approximation and Hamilton-Jacobi method to solve the Klein-Gordon equation for outgoing trajectories. We find the tunneling probability of outgoing charged and uncharged scalars from the event horizon of black strings, and hence the Hawking temperature for these black configurations.

The behavior of the timelike and null geodesics of charged E. Ay$\\acute{o}$n-Beato and A. Garcia (ABG) black hole are investigated. For circular and radial geodesics, we investigate all the possible motions by plotting the effective potentials for different parameters. In conclusion, we have shown that there is no phenomenon of \\textit{superradiance} in this case.

Recently, a new framework for solving the hierarchy problem was proposed which does not rely on low energy supersymmetry or technicolor. The fundamental Planck mass is at a TeV and the observed weakness of gravity at long distances is due the existence of new sub-millimeter spatial dimensions. In this letter, we study how the properties of black holes are altered in these theories. Small black holes---with Schwarzschild radii smaller than the size of the new spatial dimensions---are quite different. They are bigger, colder, and longer-lived than a usual $(3+1)$-dimensional black hole of the same mass. Furthermore, they primarily decay into harmless bulk graviton modes rather than standard-model degrees of freedom. We discuss the interplay of our scenario with the holographic principle. Our results also have implications for the bounds on the spectrum of primordial black holes (PBHs) derived from the photo-dissociation of primordial nucleosynthesis products, distortion of the diffuse gamma-ray spectrum, overcl...

... It seems likely that elliptical galaxies contain massive 'black holes'?objects collapsed within their Schwarzschild radii?in their nuclei (see, for example, Wolfe and Burbidge2). The principal ... seems to be required to power the observed phenomena. For such a mass, the Schwarzschild radius (R s) is about 10?4 pc; for a mass of 1011 ...

In this paper we present an exact solution of Einstein's field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type $D$ in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole.

Gravitationally bound supermassive black hole binaries (SBHBs) are thought to be a natural product of galactic mergers and growth of the large scale structure in the universe. They however remain observationally elusive, thus raising a question about characteristic observational signatures associated with these systems. In this conference proceeding I discuss current theoretical understanding and latest advances and prospects in observational searches for SBHBs.

......to the four-dimensional Schwarzschild solution, there is no room...deformed from an ordinary Schwarzschild black hole and the radiation...gravitational attraction from its mirror image on the other side of...The attraction from the mirror image will not be larger than......

... thin ring in a circular orbit at radius R = r GM/c2 around a Schwarzschild black hole of mass M, the two emission peaks will be at wavelengths given ... we would expect the profiles of the emission peaks at any given time to be mirror images of each other (at least on timescales longer than the orbital time). ...

We study the velocity dispersion profiles of the nuclei of NGC 1326, 2685, 5273 and 5838 in the CO first overtone band. There is evidence for a black hole (BH) in NGC 1326 and 5838. Gas is seen flowing out of the nuclear region of NGC 5273. We put upper limits on the nuclear BHs responsible for its activity and that of NGC 2685.

Savannah River National Laboratory Meets with Historically Black Savannah River National Laboratory Meets with Historically Black Colleges and Universities Savannah River National Laboratory Meets with Historically Black Colleges and Universities February 1, 2013 - 9:00am Addthis South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the laboratory and seven historically black colleges and universities. South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the laboratory and seven historically black colleges and universities.

Savannah River National Laboratory Meets with Historically Black Savannah River National Laboratory Meets with Historically Black Colleges and Universities Savannah River National Laboratory Meets with Historically Black Colleges and Universities February 1, 2013 - 9:00am Addthis South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the laboratory and seven historically black colleges and universities. South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the laboratory and seven historically black colleges and universities.

The radial motion along null geodesics in static charged black hole space-times, in particular, the Reissner-Nordstr\\"om and stringy charged black holes are studied. We analyzed the properties of the effective potential. The circular photon orbits in these space-times are investigated. We found that the radius of circular photon orbits in both charged black holes are different and differ from that given in Schwarzschild space-time. We studied the physical effects of the gravitational field between two test particles in stringy charged black hole and compared the results with that given in Schwarzschild and Reissner-Nordstr\\"om black holes.

Black Carbon Soot Impact on Snow Albedo: A Laboratory Investigation Black Carbon Soot Impact on Snow Albedo: A Laboratory Investigation Speaker(s): Odelle Hadley Date: August 13, 2009 - 12:00pm Location: 90-3075 This presentation examines the changing cryosphere and specifically the role of black carbon on the reflectivity of snow. Small amounts of black carbon in snow purportedly contribute to a reduction in snow albedo, contributing to regional climate change and early onset of melting. Our current research focuses on the connection between black carbon and albedo reduction. This presentation will describe our laboratory experiments wherein we make and characterize pure and contaminated snow and assess the black carbon snow albedo reduction as a function of black carbon mixing ratio and snow grain size. Experimental results are compared to verify or

We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back towards the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (i) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (ii) random orientations of successive accretion disk episodes; (iii) the possibility of rapid SMBH growth; (iv) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible fl...

In this paper, we derive rotating black string solutions in the presence of two kinds of nonlinear electromagnetic fields, so-called Born-Infeld and power Maxwell invariant. Investigation of the solutions show that for the Born-Infeld black string the singularity is timelike and the asymptotic behavior of the solutions is anti-de Sitter, but for power Maxwell invariant solutions, depending on the values of nonlinearity parameter, the singularity may be timelike as well as spacelike and the solutions are not asymptotically anti-de Sitter for all values of the nonlinearity parameter. Next, we calculate the conserved quantities of the solutions by using the counterterm method, and find that these quantities do not depend on the nonlinearity parameter. We also compute the entropy, temperature, the angular velocity, the electric charge, and the electric potential of the solutions, in which the conserved and thermodynamics quantities satisfy the first law of thermodynamics.

We study the properties of the space of thermodynamic equilibrium states of the Ba\\~nados-Teitelboim-Zanelli (BTZ) black hole in (2+1)-gravity. We use the formalism of geometrothermodynamics to introduce in the space of equilibrium states a $2-$dimensional thermodynamic metric whose curvature is non-vanishing, indicating the presence of thermodynamic interaction, and free of singularities, indicating the absence of phase transitions. Similar results are obtained for generalizations of the BTZ black hole which include a Chern-Simons term and a dilatonic field. Small logarithmic corrections of the entropy turn out to be represented by small corrections of the thermodynamic curvature, reinforcing the idea that thermodynamic curvature is a measure of thermodynamic interaction.

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Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class.Quant.Grav.27:114005,2010], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculation was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features.

The origin of the high energy emission (X-rays and gamma-rays) from black holes is still a matter of debate. We present new evidence that hard X-ray emission in the low/hard state may not be dominated by thermal Comptonization. We present an alternative scenario for the origin of the high energy emission that is well suited to explain the high energy emission from GRO J1655-40.

We consider the production of primordial micro black holes (MBH) remnants in the early Universe. These objects induce the Universe to be in a matter-dominated era before the onset of inflation. Effects of such an epoch on the CMB power spectrum are discussed and computed both analytically and numerically. By comparison with the latest observational data from the WMAP collaboration, we find that our model appears to explain the quadrupole anomaly of the CMB power spectrum.

There are models of gravitational collapse in classical general relativity which admit the formation of naked singularities as well as black holes. These include fluid models as well as models with scalar fields as matter. Even if fluid models were to be regarded as unphysical in their matter content, the remaining class of models (based on scalar fields) generically admit the formation of visible regions of finite but arbitrarily high curvature. Hence it is of interest to ask, from the point of view of astrophysics, as to what a stellar collapse leading to a naked singularity (or to a visible region of very high curvature) will look like, to a far away observer. The emission of energy during such a process may be divided into three phases - (i) the classical phase, during which matter and gravity can both be treated according to the laws of classical physics, (ii) the semiclassical phase, when gravity is treated classically but matter behaves as a quantum field, and (iii) the quantum gravitational phase. In this review, we first give a summary of the status of naked singularities in classical relativity, and then report some recent results comparing the semiclassical phase of black holes with the semiclassical phase of spherical collapse leading to a naked singularity. In particular, we ask how the quantum particle creation during the collapse leading to a naked singularity compares with the Hawking radiation from a star collapsing to form a black hole. It turns out that there is a fundamental difference between the two cases. A spherical naked star emits only about one Planck energy during its semiclassical phase, and the further evolution can only be determined by the laws of quantum gravity. This contrasts with the semiclassical evaporation of a black hole.

We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

In this paper, we firstly prove that the adiabatic invariant quantity, which is commonly used in the literature for quantizing the rotating black holes (BHs) is fallacious. We then show how its corrected form should be. The main purpose of this paper is to study the quantization of 4-dimensional rotating linear dilaton black hole (RLDBH) spacetime describing with an action, which emerges in the Einstein-Maxwell-Dilaton-Axion (EMDA) theory. The RLDBH spacetime has a non-asymptotically flat (NAF) geometry. They reduces to the linear dilaton black hole (LDBH) metric when vanishing its rotation parameter $a$. While studying its scalar perturbations, it is shown that the Schr\\"odinger-like wave equation around the event horizon reduces to a confluent hypergeometric differential equation. Then the associated complex frequencies of the quasinormal modes (QNMs) are computed. By using those QNMs in the true definition of the rotational adiabatic invariant quantity, we obtain the quantum spectra of entropy/area for the RLDBH. It is found out that both spectra are discrete and equidistant. Besides, we reveal that the quantum spectra do not depend on $a$ in spite of the QNMs are modulated by it.

We show that there is a classical metric satisfying the Einstein equations outside a finite spacetime region where matter collapses into a black hole and then emerges from a white hole. We compute this metric explicitly. We show how quantum theory determines the (long) time for the process to happen. A black hole can thus quantum-tunnel into a white hole. For this to happen, quantum gravity should affect the metric also in a small region outside the horizon: we show that contrary to what is commonly assumed, this is not forbidden by causality or by the semiclassical approximation, because quantum effects can pile up over a long time. This scenario alters radically the discussion on the black hole information puzzle.

Black Carbon Emissions by Rocket Engines Types of rocket engines Emissions Liquid Hydrogen. Note: Black carbon does not deplete ozone. What happens is the black carbon emissions from the rocket. Other black carbon emissions: The number one contributor to black carbon is burning biomass. Also

govCampaignsCharacterization of Black Carbon Mixing State govCampaignsCharacterization of Black Carbon Mixing State Related Campaigns Characterization of Black Carbon Mixing State - II 2014.02.15, Sedlacek, OSC Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Characterization of Black Carbon Mixing State 2012.11.01 - 2013.06.14 Lead Scientist : Arthur Sedlacek For data sets, see below. Description The objective of the proposed experiments was to characterize the mixing state of black carbon produced in biomass burning using the single particle soot photometer (SP2). The large uncertainty associated with black carbon (BC) direct forcing is due, in part, to the dependence of light absorption of BC-containing particles on the position of the BC aggregate within the particle. It is

Black Hills Energy - Solar Power Program Black Hills Energy - Solar Power Program Black Hills Energy - Solar Power Program < Back Eligibility Commercial Fed. Government General Public/Consumer Industrial Local Government Nonprofit Residential Schools State Government Savings Category Solar Buying & Making Electricity Program Info Start Date 7/1/2006 State Colorado Program Type Performance-Based Incentive Rebate Amount Systems up to 10 kW: $0.1267/kWh (only for first 5 kW) Systems larger than 10 kW up to 100 kW: $0.16/kWh Provider Black Hills Energy Black Hills Energy has a performance-based incentive (PBI) for photovoltaic (PV) systems up to 100 kilowatts (kW) in capacity. In exchange for these incentives, Black Hills Energy earns the right to the renewable energy credits (RECs) associated with the PV-generated electricity for a period of

A new approach to the study of the AGN phenomenon is proposed, in which the nucleus activity is related to the metric of the inner massive black hole. The possibility of a Toroidal Black Hole (TBH), in contrast to the usual Spherical Black Hole (SBH), is discussed as a powerful tool in understanding AGN related phenomena, such as the energetics, the production of jets and the acceleration of particles, the shape of the magnetic field and the lifetime of nucleus activity.

Hawking radiation has been studied as a phenomenon of quantum tunneling in different black holes. In this paper we extend this semi-classical approach to cylindrically symmetric black holes. Using the Hamilton-Jacobi method and WKB approximation we calculate the tunneling probabilities of incoming and outgoing Dirac particles from the event horizon and find the Hawking temperature of these black holes. We obtain results both for uncharged as well as charged particles.

A quantum-mechanical prescription of static Einstein field equation is proposed in order to construct the matter-metric eigen-states in the interior of a static Schwarzschild black hole where the signature of space-time is chosen as (--++). The spectrum of the quantum states is identified to be the integral multiples of the surface gravity. A statistical explanation of black hole entropy is given and a quantisation rule for the masses of Schwarzschild black holes is proposed.

The eventual production of mini black holes by proton-proton collisions at the LHC is predicted by theories with large extra dimensions resolvable at the Tev scale of energies. It is expected that these black holes evaporate shortly after its production as a consequence of the Hawking radiation. We show that for theories based on the ADS/CFT correspondence, the produced black holes may have an unstable horizon, which grows proportionally to the square of the distance to the collision point.

We show that any nonextreme black hole can be described by a state with $L_0=E_R$ in a $D=2$ chiral conformal field theory with central charge $c=12E_R$ where $E_R$ is the dimensionless Rindler energy of the black hole. The theory lives in the very near horizon region, i.e. around the origin of Rindler space. Black hole hair is the momentum along the Euclidean dimensionless Rindler time direction. As evidence, we show that $D$--dimensional Schwarzschild black holes and $D=2$ dilatonic ones that are obtained from them by spherical reduction are described by the same conformal field theory states.

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Metal blacks are used as catalysts in a number of organic synthesis processes. Using the method of matrix insulation of blacks obtained from organometallic compounds in the inert atmosphere the IR spectra have been recorded for carbon monoxide adsorbed on actual palladium blacks. The controllable mild conditions for reduction of the initial complex by hydrazine hydrate provide a means of separating the intermediate states of this process. By discontinuing at various stages the reduction of the organometallic complex being investigated the authors have obtained IR spectra of carbon monoxide characterizing the stages of forming the metallic palladium black.

A perturbative analysis shows that black holes do not remember the value of the scalar field ? at the time they formed if ? changes in tensor-scalar cosmology. Moreover, even when the black hole mass in the Einstein frame is approximately unaffected by the changing of ?, in the Jordan-Fierz frame the mass increases. This mass increase requires a reanalysis of the evaporation of primordial black holes in tensor-scalar cosmology. It also implies that there could have been a significant magnification of the (Jordan-Fierz frame) mass of primordial black holes.

Recent observations of Sgr A* give strong constraints for possible models of the physical nature of Sgr A* and suggest the presence of a massive black~hole with M0.9) accreting 10^-8.5 - 10^-7 M_sun/yr at a black~hole mass of M=2 10^6 M_sunseen almost edge on. A low mass black hole of M' together with simple scaling laws to provide an easy-to-handle test for the black hole model.

We obtain the mass expression of the three- and five-dimensional Lifshitz black holes by em- ploying the recently proposed quasilocal formulation of conserved charges, which is based on the off-shell extension of the ADT formalism. Our result is consistent with the first law of black hole thermodynamics and resolves the reported discrepancy between the ADT formalism and the other conventional methods. The same mass expression of Lifshitz black holes is obtained by using an- other quasilocal method by Padmanabhan. We also discuss the reported discrepancy in the context of the extended first law of black hole thermodynamics by allowing the pressure term.

We show that the low frequency absorption cross section of minimally coupled massless scalar fields by extremal spherically symmetric black holes in d dimensions in the presence of string-theoretical alpha' corrections is equal to the horizon area. Classically one has the relation sigma=4GS between the absorption cross section and the black hole entropy. We discuss the validity of such relation in the presence of alpha' corrections for extremal black holes, both nonsupersymmetric and supersymmetric. The examples we consider seem to indicate that this relation is verified in the presence of alpha' corrections for supersymmetric black holes, but not for nonsupersymmetric ones.

Employing higher-order perturbation theory, we find a new class of charged rotating black hole solutions of Einstein-Maxwell-dilaton theory with general dilaton coupling constant. Starting from the Myers-Perry solutions, we use the electric charge as the perturbative parameter, and focus on extremal black holes with equal-magnitude angular momenta in odd dimensions. We perform the perturbations up to 4th order for black holes in 5 dimensions and up to 3rd order in higher odd dimensions. We calculate the physical properties of these black holes and study their dependence on the charge and the dilaton coupling constant.

Employing higher order perturbation theory, we find a new class of charged rotating black hole solutions of Einstein-Maxwell-dilaton theory with general dilaton coupling constant. Starting from the Myers-Perry solutions, we use the electric charge as the perturbative parameter, and focus on extremal black holes with equal-magnitude angular momenta in odd dimensions. We perform the perturbations up to 4th order for black holes in 5 dimensions and up to 3rd order in higher odd dimensions. We calculate the physical properties of these black holes and study their dependence on the charge and the dilaton coupling constant.

This paper is devoted to study the geodesic structure of regular Hayward black hole. The timelike and null geodesic have been studied explicitly for radial and non-radial motion. For timelike and null geodesic in radial motion there exists analytical solution, while for non-radial motion the effective potential has been plotted, which investigates the position and turning points of the particle. It has been found that massive particle moving along timelike geodesics path are dragged towards the BH and continues move around BH in particular orbits.

We consider the most general non-Hermitian Hulthen potential to study the scattering of spin-less relativistic particles. The conditions for CC, SS and CPA are obtained analytically for this potential. We show that almost total absorption occurs for entire range of incidence energy for certain parameter ranges of the potential and hence term this as `black potential'. Time reversed of the same potential shows perfect emission for the entire range of particle energy. We also present the classical analog of this potential in terms of waveguide cross section.

It is shown that the surface gravity and temperature of a stationary black hole are invariant under conformal transformations of the metric that are the identity at infinity. More precisely, we find a conformal invariant definition of the surface gravity of a conformal Killing horizon that agrees with the usual definition(s) for a true Killing horizon and is proportional to the temperature as defined by Hawking radiation. This result is reconciled with the intimate relation between the trace anomaly and the Hawking effect, despite the {\\it non}invariance of the trace anomaly under conformal transformations.

We apply the generalized second law of thermodynamics and derive upper limits on the variation in the fundamental constants. The maximum variation in the electronic charge permitted for black holes accreting and emitting in the present cosmic microwave background corresponds to a variation in the fine-structure constant of {delta}{alpha}/{alpha}{approx_equal}2x10{sup -23} per second. This value matches the variation measured by Webb et al. [Phys. Rev. Lett. 82, 884 (1999); Phys. Rev. Lett. 87, 091301 (2001)] using absorption lines in the spectra of distant quasars and suggests the variation mechanism may be a coupling between the electron and the cosmic photon background.

We show that black holes fulfill the scaling laws arising in critical transitions. In particular, we find that in the transition from negative to positive values the heat capacities $C_{JQ}$, $C_{\\Omega Q}$ and $C_{J\\Phi}$ give rise to critical exponents satisfying the scaling laws. The three transitions have the same critical exponents as predicted by the universality Hypothesis. We also briefly discuss the implications of this result with regards to the connections among gravitation, quantum mechanics and statistical physics.

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We investigate possible signatures of black hole events at the LHC in the hypothesis that such objects will not evaporate completely, but leave a stable remnant. For the purpose of defining a reference scenario, we have employed the publicly available Monte Carlo generator CHARYBDIS2, in which the remnant's behavior is mostly determined by kinematic constraints and conservation of some quantum numbers, such as the baryon charge. Our findings show that electrically neutral remnants are highly favored and a significantly larger amount of missing transverse momentum is to be expected with respect to the case of complete decay.

We study thermodynamic quantities of an acoustic black hole and its thermodynamic stability in a cavity based on the generalized uncertainty principle. It can be shown that there is a minimal black hole which can be a stable remnant after black hole evaporation. Moreover, the behavior of the free energy shows that the large black hole is stable too. Therefore, the acoustic black hole can decay into the remnant or the large black hole.

Intermediate-mass black holes (IMBHs), with masses of hundreds to thousands of solar masses, will be unique sources of gravitational waves for LISA. Here we discuss their context as well as specific characteristics of IMBH-IMBH and IMBH-supermassive black hole mergers and how these would allow sensitive tests of the predictions of general relativity in strong gravity.

Accelerating and rotating black holes J. B. Griffiths1 and J. PodolskÂ´y2 1Department Abstract An exact solution of Einstein's equations which represents a pair of accelerating and rotating which explicitly contains the known special cases for either rotating or accelerating black holes

and the nearÂ­ est black pixel. The EDM plays an important role in machine vision, pattern recognitionTitle page 1 #12; 1 Introduction The Euclidean distance map (EDM) of a black and white n 2 n binary, and robotics[9]. Many algorithms have been proposed for comÂ­ puting the EDM. Yamada[10] presented an EDM

......research-article Articles The third law of thermodynamics for Kerr black holes Isao...condition under which the third law of black-hole thermodynamics for Kerr holes is not violated...diverge to infinity as a power law for , and therefore no Kerr......

Synchronous Black Hole Search in Directed Graphs Adrian Kosowski Alfredo Navarra Cristina M called black hole nodes, and once a robot enters in one of them, it is destroyed. The goal is to find supported by the Italian CNR Short-Term Mobility Program. A. Kosowski was supported Polish Ministry Grant N

There are many models relating an accretion disk of Black Hole to jet outflow. The herein heuristic model describes the continuation of an external accretion disk to an internal accretion disk for less than Black Hole horizon, and subsequent polar jet outflow along polar axis out of polar vortex wherein the event horizon is no longer descriptive.

We elucidate the `right' process for energy extraction from Kerr black holes through `FFDE' magnetospheres, free from causality violation. It is shown that the magnetosphere of a Kerr black hole possesses the double-structure, consisting of the inner and outer magnetospheres with the pair-creation gap between them and with respective unipolar batteries at the inner and outer surfaces of the gap.

Recently, Durkee and Reall have conjectured a criterion for linear instability of rotating, extremal, asymptotically Minkowskian black holes in $d\\ge 4$ dimensions, such as the Myers-Perry black holes. They considered a certain elliptic operator, $\\cal A$, acting on symmetric traceless tensors intrinsic to the horizon. Based in part on numerical evidence, they suggested that if the lowest eigenvalue, $\\lambda$, of this operator is less than the critical value $-1/4$ ( called "effective BF-bound"), then the black hole is linearly unstable. In this paper, we prove their conjecture. Our proof uses a combination of methods such as (i) the "canonical energy method" of Hollands-Wald, (ii) algebraically special properties of the near horizon geometries associated with the black hole, and (iii) the structure of the (linearized) constraint equations. Our method of proof is also applicable to rotating, extremal asymptotically Anti-deSitter black holes. In that case, our methods show that "all" such black holes are unstable. Although we explicitly discuss in this paper only extremal black holes, we argue that our methods can be generalized straightforwardly to obtain the same results for "near" extremal black holes.

NSA-OBS) NSA-OBS) The NSA-OBS site from the air. This aerial shot of the OBS site shows the generator in the lower-right corner, one of the huts in the upper-left corner, and part of the boardwalk leading away from the hut. View an aerial photo-map of the NSA-OBS site. OBS spruce trees and flux tower The road to the OBS site. The road to the OBS site was often a muddy mess, accessable only by ARGO all-terrain vehicles, and even they got stuck often. The OBS flux tower The NSA black spruce carbon model evaluation site and TE canopy access tower. Oblique view of the trail leading into the NSA Old Black Spruce site. Highway 391 is beyond the image at the bottom and the power line is viewable at the top of the image. The NSA-OBS site would be off to the upper left. The NSA-OBS Rohn tower where Amar Bazzaz of Harvard University is climbing the tower for maintenance.

Primordial black holes (PBHs) are theoretical black holes which may be formed during the radiation dominant era and, basically, caused by the gravitational collapse of radiational overdensities. It has been well known that in the context of the structure formation in our Universe such collapsed objects, e.g., halos/galaxies, could be considered as bias tracers of underlying matter fluctuations and the halo/galaxy bias has been studied well. Employing a peak-background split picture which is known to be a useful tool to discuss the halo bias, we consider the large scale clustering behavior of the PBH and propose an almost mass-independent constraint to the scenario that dark matters (DMs) consist of PBHs. We consider the case where the statistics of the primordial curvature perturbations is almost Gaussian, but with small local-type non-Gaussianity. If PBHs account for the DM abundance, such a large scale clustering of PBHs behaves as nothing but the matter isocurvature perturbation and constrained strictly by...

Radiation emitted near a black hole reaches the observer by multiple paths; and when this radiation varies in time, the time-delays between the various paths generate a "blinking" effect in the observed light curve L(t) or its auto-correlation function xi(T)= . For the particularly important "face-on" configuration (in which the hole is viewed roughly along its spin axis, while the emission comes roughly from its equatorial plane -- e.g. from the inner edge of its accretion disk, or from the violent flash of a nearby/infalling star) we calculate the blinking in detail by computing the time delay Delta t_{j}(r,a) and magnification mu_{j}(r,a) of the jth path (j=1,2,3,...), relative to the primary path (j=0), as a function of the emission radius r and black hole spin 0

Recently, a general analysis has been given of the stability with respect to axisymmetric perturbations of stationary-axisymmetric black holes and black branes in vacuum general relativity in arbitrary dimensions. It was shown that positivity of canonical energy on an appropriate space of perturbations is necessary and sufficient for stability. However, the notions of both "stability" and "instability" in this result are significantly weaker than one would like to obtain. In this paper, we prove that if a perturbation of the form $\\pounds_t \\delta g$---with $\\delta g$ a solution to the linearized Einstein equation---has negative canonical energy, then that perturbation must, in fact, grow exponentially in time. The key idea is to make use of the $t$- or ($t$-$\\phi$)-reflection isometry, $i$, of the background spacetime and decompose the initial data for perturbations into their odd and even parts under $i$. We then write the canonical energy as $\\mathscr E\\ = \\mathscr K + \\mathscr U$, where $\\mathscr K$ and $...

With the puncture method for black hole simulations, the second infinity of a wormhole geometry is compactified to a single 'puncture point' on the computational grid. The region surrounding the puncture quickly evolves to a trumpet geometry. The computational grid covers only a portion of the trumpet throat. It ends at a boundary whose location depends on resolution. This raises the possibility that perturbations in the trumpet geometry could propagate down the trumpet throat, reflect from the puncture boundary, and return to the black hole exterior with a resolution-dependent time delay. Such pathological behavior is not observed. This is explained by the observation that some perturbative modes propagate in the conformal geometry, others propagate in the physical geometry. The puncture boundary exists only in the physical geometry. The modes that propagate in the physical geometry are always directed away from the computational domain at the puncture boundary. The finite difference stencils ensure that these modes are advected through the boundary with no coupling to the modes that propagate in the conformal geometry. These results are supported by numerical experiments with a code that evolves spherically symmetric gravitational fields with standard Cartesian finite difference stencils. The code uses the Baumgarte-Shapiro-Shibata-Nakamura formulation of Einstein's equations with 1+log slicing and gamma-driver shift conditions.

Brown, J. David [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)

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The ~15 members of the Aspergillus section Nigri species complex (the "Black Aspergilli") are significant as platforms for bioenergy and bioindustrial technology, as members of soil microbial communities and players in the global carbon cycle, and as food processing and spoilage agents and agricultural toxigens. Despite their utility and ubiquity, the morphological and metabolic distinctiveness of the complex's members, and thus their taxonomy, is poorly defined. We are using short read pyrosequencing technology (Roche/454 and Illumina/Solexa) to rapidly scale up genomic and transcriptomic analysis of this species complex. To date we predict 11197 genes in Aspergillus niger, 11624 genes in A. carbonarius, and 10845 genes in A. aculeatus. A. aculeatus is our most recent genome, and was assembled primarily from 454-sequenced reads and annotated with the aid of >2 million 454 ESTs and >300 million Solexa ESTs. To most effectively deploy these very large numbers of ESTs we developed 2 novel methods for clustering the ESTs into assemblies. We have also developed a pipeline to propose orthologies and paralogies among genes in the species complex. In the near future we will apply these methods to additional species of Black Aspergilli that are currently in our sequencing pipeline.

Partnerships with Historically Black Colleges and Partnerships with Historically Black Colleges and Universities Strengthening Our Partnerships with Historically Black Colleges and Universities January 13, 2011 - 6:06pm Addthis Strengthening Our Partnerships with Historically Black Colleges and Universities Secretary Chu Secretary Chu Former Secretary of Energy Last February, President Obama renewed the White House Initiative on Historically Black Colleges and Universities to encourage collaboration between government agencies, educational associations, philanthropic organizations, the private sector and others to increase the capacity of HBCUs to provide high-quality education to a greater number of students. The Department of Energy is committed to supporting education at HBCUs and has partnered with HBCUs on a variety of projects. As part of that

The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black hole. In this paper, we demonstrate that binary stars can be ejected out of the Galactic center with velocities up to 10^3 km/s, while preserving their integrity, through interactions with a massive binary black hole. Binary stars are unlikely to attain such high velocities via scattering by a single massive black hole or through any other mechanisms. Based on the above theoretical prediction, we propose a search for binary systems among the hypervelocity stars. Discovery of hypervelocity binary stars, even one, is a definitive evidence of the existence of a massive binary black hole in the Galactic center.

The existence of extra degrees of freedom beyond the electroweak scale may allow the formation of black holes in nearly horizontal neutrino air showers. In this paper we examine the average properties of the light descendants of these black holes. Our analysis indicates that black hole decay gives rise to deeply penetrating showers with an electromagnetic component which differs substantially from that in conventional neutrino interactions, allowing a good characterization of the phenomenon against background. Naturally occurring black holes in horizontal neutrino showers could be detected and studied with the Auger air shower array. Since the expected black hole production rate at Auger is $> 1$ event/year, this cosmic ray observatory could be potentially powerful in probing models with extra dimensions and TeV-scale gravity.

We study the low-temperature expansion of the first law of thermodynamics for near-extremal black holes. We show that for extremal black holes with nonvanishing entropy, the leading-order contribution yields an expression for their extremal entropy that is in agreement with the entropy-function result. When their entropy vanishes due to the vanishing of a one-cycle on the horizon, such a leading contribution is always compatible with the first law satisfied by a Bañados-Teitelboim-Zanelli black hole. The universality of these results follows from universal facts about extremal black holes. Our results are consistent with both the presence of local AdS2 and AdS3 near-horizon throats for extremal black holes and with the suggested quantum microscopic descriptions (AdS2/CFT1, Kerr/CFT, and extremal vanishing horizon/CFT).

of their privileged position in society, whites life situations had never had necessitated that they learn about the black co-culture. The black partners also reported seeing the white community differently by understanding the nuances of racism at a deeper level...

will inject CO will inject CO 2 into a coalbed methane (CBM) well in Tuscaloosa County, Alabama, to assess the capability of mature CBM reservoirs to receive and adsorb large volumes of CO 2 . Injection began at the test site on June 15; the site was selected because it is representative of the 23,000- square-mile Black Warrior Basin located in northwestern Alabama and northeastern Mississippi. It is estimated that this area has the potential to store in the range of 1.1 to 2.3 Gigatons of CO 2 , which is approximately the amount that Alabama's coal-fired power plants emit in two decades. The targeted coal seams range from 940 to 1,800 feet deep and are one to six feet thick. Approximately 240 tons of CO 2 will be injected over a 45- to 60-day period. More information

We review recent progress in applying the AdS/CFT correspondence to finite-temperature field theory. In particular, we show how the hydrodynamic behavior of field theory is reflected in the low-momentum limit of correlation functions computed through a real-time AdS/CFT prescription, which we formulate. We also show how the hydrodynamic modes in field theory correspond to the low-lying quasinormal modes of the AdS black p-brane metric. We provide a proof of the universality of the viscosity/entropy ratio within a class of theories with gravity duals and formulate a viscosity bound conjecture. Possible implications for real systems are mentioned.

Not only is the Bekenstein expression for the entropy of a black hole a convex function of the energy, rather than being a concave function as it must be, it predicts a final equilibrium temperature given by the harmonic mean. This violates the third law, and the principle of maximum work. The property that means are monotonically increasing functions of their argument underscores the error of transferring from temperature means to means in the internal energy when the energy is not a monotonically increasing function of temperature. Whereas the former leads to an increase in entropy, the latter lead to a decrease in entropy thereby violating the second law. The internal energy cannot increase at a slower rate than the temperature itself.

The super-massive 4 million solar mass black hole Sagittarius~A* (SgrA*) shows flare emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a statistical way. The analysis shows that the near-infrared flare amplitudes are dominated by a single state power law, with the low states in SgrA* limited by confusion through the unresolved stellar background. There are several dusty objects in the immediate vicinity of SgrA*. The source G2/DSO is one of them. Its nature is unclear. It may be comparable to similar stellar dusty sources in the region or may consist predominantly of gas and dust. In this case a particularly enhanced accretion activity onto SgrA* may be expected in the near future. Here the interpretation of recent data and ongoing observations are discussed.

Many of the recent numerical simulations of binary black holes in vacuum adopt the moving puncture approach. This successful approach avoids the need to impose numerical excision of the black hole interior and is easy to implement. Here we wish to explore how well the same approach can be applied to moving black hole punctures in the presence of relativistic hydrodynamic matter. First, we evolve single black hole punctures in vacuum to calibrate our Baumgarte-Shapiro-Shibata-Nakamura implementation and to confirm that the numerical solution for the exterior spacetime is invariant to any junk (i.e., constraint-violating) initial data employed in the black hole interior. Then we focus on relativistic Bondi accretion onto a moving puncture Schwarzschild black hole as a numerical test bed for our high-resolution shock-capturing relativistic hydrodynamics scheme. We find that the hydrodynamical equations can be evolved successfully in the interior without imposing numerical excision. These results help motivate the adoption of the moving puncture approach to treat the binary black hole-neutron star problem using conformal thin-sandwich initial data.

We study the thermodynamic properties associated with the black hole horizon and cosmological horizon for the Gauss-Bonnet solution in de Sitter space. When the Gauss-Bonnet coefficient is positive, a locally stable small black hole appears in the case of spacetime dimension d=5, the stable small black hole disappears, and the Gauss-Bonnet black hole is always unstable quantum mechanically when d>~6. On the other hand, the cosmological horizon is found to be always locally stable independent of the spacetime dimension. But the solution is not globally preferred; instead, the pure de Sitter space is globally preferred. When the Gauss-Bonnet coefficient is negative, there is a constraint on the value of the coefficient, beyond which the gravity theory is not well defined. As a result, there is not only an upper bound on the size of black hole horizon radius at which the black hole horizon and cosmological horizon coincide with each other, but also a lower bound depending on the Gauss-Bonnet coefficient and spacetime dimension. Within the physical phase space, the black hole horizon is always thermodynamically unstable and the cosmological horizon is always stable; furthermore, as in the case of the positive coefficient, the pure de Sitter space is still globally preferred. This result is consistent with the argument that the pure de Sitter space corresponds to an UV fixed point of dual field theory.

We discuss in the framework of black hole thermodynamics some aspects relative to the third law in the case of black holes of the Kerr-Newman family. In the light of the standard proof of the equivalence between the unattainability of the zero temperature and the entropic version of the third law it is remarked that the unattainability has a special character in black hole thermodynamics. Also the zero temperature limit which obtained in the case of very massive black holes is discussed and it is shown that a violation of the entropic version in the charged case occurs. The violation of the Bekenstein-Hawking law in favour of zero entropy S_E=0 in the case of extremal black holes is suggested as a natural solution for a possible violation of the second law of thermodynamics. Thermostatic arguments in support of the unattainability are explored, and $S_E=0$ for extremal black holes is shown to be again a viable solution. The third law of black hole dynamics by W.Israel is then interpreted as a further strong corroboration to the picture of a discontinuity between extremal states and non-extremal ones.

National Conference of Black Mayors, Inc. National Conference of Black Mayors, Inc. Initiative: Partnered in developing the 1997 Environmental Justice conference, "The State of Environmental Justice in America" Cooperative Agreement, created in 1999 * Goal * Technical Assistance * Communities Served * Community Impact Goal: The cooperative agreement enhances the National Conference of Black Mayors, Inc. (NCBM) members' capacity for energy and environmental planning through computer-based technology, Internet access and a training workshop. Technical Assistance: The NCBM will establish a formal relationship with DOE's Dr. Samuel P. Massie Chairs of Excellence Program participants. The Massie Chairs of Excellence Program partnership will provide the NCBM's members with technical assistance in the environmental

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In this article we analyze the geodesics of test particles and light in the five dimensional (charged) doubly spinning black ring spacetime. Apparently it is not possible to separate the Hamilton-Jacobi-equation for (charged) doubly spinning black rings in general, so we concentrate on special cases: null geodesics in the ergosphere and geodesics on the two rotational axes of the (charged) doubly spinning black ring. We present analytical solutions to the geodesic equations for these special cases. Using effective potential techniques we study the motion of test particles and light and discuss the corresponding orbits.

We study the absorption probability and Hawking radiation of the scalar field in the rotating G\\"{o}del black hole in minimal five-dimensional gauged supergravity. We find that G\\"{o}del parameter $j$ imprints in the greybody factor and Hawking radiation. It plays a different role from the angular momentum of the black hole in the Hawking radiation and super-radiance. These information can help us know more about rotating G\\"{o}del black holes in minimal five-dimensional gauged supergravity.

The objective of this study is to determine whether a safeguards approach can be developed for “black box” processes or facilities. These are facilities where a State or operator may limit IAEA access to specific processes or portions of a facility; in other cases, the IAEA may be prohibited access to the entire facility. The determination of whether a black box process or facility is safeguardable is dependent upon the details of the process type, design, and layout; the specific limitations on inspector access; and the restrictions placed upon the design information that can be provided to the IAEA. This analysis identified the necessary conditions for safeguardability of black box processes and facilities.

Thermal radiations from spherically symmetric black holes have been studied from the point of view of quantum tunneling. In this paper we extend this approach to study radiation of fermions from charged and rotating black strings. Using WKB approximation and Hamilton-Jacobi method we work out the tunneling probabilities of incoming and outgoing fermions and find the correct Hawking temperature for these objects. We show that in appropriate limits the results reduce to those for the uncharged and non-rotating black strings.

We examine the accretion process onto the black hole with a string cloud background, where the horizon of the black hole has an enlarged radius $r_H=2 M/(1-\\alpha)$, due to the string cloud parameter $\\alpha\\; (0 \\leq \\alpha cloud parameter $\\alpha$. We also find the gas compression ratios and temperature profiles below the accretion radius and at the event horizon. It is shown that the mass accretion rate, for both the relativistic and the non-relativistic fluid by a black hole in the string cloud model, increases with increase in $\\alpha$.

We discuss a sufficiently large 4-dimensional Schwarzschild black hole which is in equilibrium with a heat bath. In other words, we consider a black hole which has grown up from a small one in the heat bath adiabatically. We express the metric of the interior of the black hole in terms of two functions: One is the intensity of the Hawking radiation, and the other is the ratio between the radiation energy and the pressure in the radial direction. Especially in the case of conformal matters we check that it is a self-consistent solution of the semi-classical Einstein equation, $G_{\\mu\

We construct black hole solutions to three-dimensional Einstein-Maxwell theory with both gravitational and electromagnetic Chern-Simons terms. These intrinsically rotating solutions are geodesically complete, and causally regular within a certain parameter range. Their mass, angular momentum and entropy are found to satisfy the first law of black hole thermodynamics. These Chern-Simons black holes admit a four-parameter local isometry algebra, which generically is sl(2,R)xR, and may be generated from the corresponding vacua by local coordinate transformations.

We investigate the black hole thermodynamics in a 'deformed' relativity framework where the energy-momentum dispersion law is Lorentz-violating and the Schwarzchild-like metric is momentum-dependent with a Planckian cutoff. We obtain net deviations of the basic thermodynamical quantities from the Hawking-Bekenstein predictions: actually, the black hole evaporation is expected to quit at a nonzero critical mass value (of the order of the Planck mass), leaving a zero temperature remnant, and avoiding a spacetime singularity. Quite surprisingly, the present semiclassical corrections to black hole temperature, entropy, and heat capacity turn out to be identical to the ones obtained within some quantum approaches.

Modern derivations of the first law of black holes appear to show that the only charges that arise are monopole charges that can be obtained by surface integrals at infinity. However, the recently discovered five dimensional black ring solutions empirically satisfy a first law in which dipole charges appear. We resolve this contradiction and derive a general form of the first law for black rings. Dipole charges do appear together with a corresponding potential. We also include theories with Chern-Simons terms and generalize the first law to other horizon topologies and more generic local charges.

We compute the scattering cross section of Reissner-Nordstr\\"om black holes for the case of an incident electromagnetic wave. We describe how scattering is affected by both the conversion of electromagnetic to gravitational radiation, and the parity-dependence of phase shifts induced by the black hole charge. The latter effect creates a helicity-reversed scattering amplitude that is non-zero in the backward direction. We show that from the character of the electromagnetic wave scattered in the backward direction it is possible, in principle, to infer if a static black hole is charged.

The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on two-point functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance.

........................................................................................................ 86 REFERENCES ................................................................................................................. 88 vii LIST OF FIGURES Page Figure 5-1. Histogram of Husband-Wife Education Difference Residuals... that a white woman’s black husband does so. These findings would suggest status exchange support for black men, not black women. In their case, endogamous intermarriage is taking place where the level of education is similar among black-white marriages...

The 3-Sphere and the Bicycling Black Rings Event Horizon #12;#12;The 3-Sphere and the Bicycling that "the bicycling black rings" are a admissible solution to the event horizon of black holes in 4 is to develop a method of visualising the bicycling black rings and other four-dimensional objects. In the end

Students, Faculty from Historically Black Colleges and Universities Students, Faculty from Historically Black Colleges and Universities Share Research with EM Laboratory in Successful Exchange Students, Faculty from Historically Black Colleges and Universities Share Research with EM Laboratory in Successful Exchange February 5, 2013 - 12:00pm Addthis South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the laboratory and seven historically black colleges and universities. South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the

Celebrating Black History Month w/ DOE's Travis Dredd Celebrating Black History Month w/ DOE's Travis Dredd Celebrating Black History Month w/ DOE's Travis Dredd February 2, 2011 - 2:49pm Addthis Travis Dredd Travis Dredd Ebony Meeks Former Assistant Press Secretary, Office of Public Affairs "As I get caught-up in my day-to-day activities, I try to remember something he once said "Do your little bit of good where you are; it's those little bits of good put together, that overwhelm the world." Travis Dredd This month, we celebrate Black History Month. Throughout February, we will introduce you to African Americans who are working to advance the President's clean energy agenda and help the Department of Energy achieve its mission. Our first profile is of Travis Dredd, Special Assistant to Secretary Chu.

Students, Faculty from Historically Black Colleges and Universities Students, Faculty from Historically Black Colleges and Universities Share Research with EM Laboratory in Successful Exchange Students, Faculty from Historically Black Colleges and Universities Share Research with EM Laboratory in Successful Exchange February 5, 2013 - 12:00pm Addthis South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the laboratory and seven historically black colleges and universities. South Carolina State University students William Dumpson, left, and Alejandra Chirino, center, talk with Savannah River National Laboratory Director Dr. Terry Michalske at a recent research exchange involving the

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We present the results of a weakly modeled burst search for gravitational waves from mergers of nonspinning intermediate mass black holes in the total mass range 100–450??M? and with the component mass ratios between 1?1 ...

...Black gold. Algae (below) produce...converted into biodiesel. CREDITS...converted to biodiesel. But the technology...need to harvest algae from large...as renewable biodiesel. Instead of growing their algae outside in the...

The primary optical caustic surface behind a Kerr black hole is a four-cusped tube displaced from the line of sight. We derive the caustic surface in the nearly asymptotic region far from the black hole through a Taylor expansion of the lightlike geodesics up to and including fourth-order terms in m/b and a/b, where m is the black hole mass, a the spin, and b the impact parameter. The corresponding critical locus in the observer's sky is elliptical and a pointlike source inside the caustics will be imaged as an Einstein cross. With regard to lensing near critical points, a Kerr lens is analogous to a circular lens perturbed by a dipole and a quadrupole potential. The caustic structure of the supermassive black hole in the Galactic center could be probed by lensing of low mass x-ray binaries in the galactic inner regions or by hot spots in the accretion disk.

We present an analytical treatment of gravitational lensing by a Kerr black hole in the weak deflection limit. Lightlike geodesics are expanded as a Taylor series up to and including third-order terms in m/b and a/b, where m is the black hole mass, a the angular momentum, and b the impact parameter of the light ray. Positions and magnifications of individual images are computed with a perturbative analysis. At this order, the degeneracy with the translated Schwarzschild lens is broken. The critical curve is still a circle displaced from the black hole position in the equatorial direction and the corresponding caustic is pointlike. The degeneracy between the black hole spin and its inclination relative to the observer is broken through the angular coordinates of the perturbed images.

The primary optical caustic surface behind a Kerr black hole is a four-cusped tube displaced from the line of sight. We derive the caustic surface in the nearly asymptotic region far from the black hole through a Taylor expansion of the lightlike geodesics up to and including fourth-order terms in m/b and a/b, where m is the black hole mass, a the spin, and b the impact parameter. The corresponding critical locus in the observer’s sky is elliptical and a pointlike source inside the caustics will be imaged as an Einstein cross. With regard to lensing near critical points, a Kerr lens is analogous to a circular lens perturbed by a dipole and a quadrupole potential. The caustic structure of the supermassive black hole in the Galactic center could be probed by lensing of low mass x-ray binaries in the galactic inner regions or by hot spots in the accretion disk.

We consider the design of strategyproof cost-sharing mechanisms. We give two simple, but extremely versatile, black-box reductions, that in combination reduce the cost-sharing mechanism-design problem to the algorithmic problem of ...

We investigate Hawking radiation from two-dimensional dilatonic black holes using standard quantization techniques. In the background of a collapsing black hole solution the Bogoliubov coefficients can be exactly determined. In the regime after the black hole has settled down to an `equilibrium' state but before the backreaction becomes important these give the known result of a thermal distribution of Hawking radiation at temperature lambda/(2pi). The density matrix is computed in this regime and shown to be purely thermal. Similar techniques can be used to derive the stress tensor. The resulting expression agrees with the derivation based on the conformal anomaly and can be used to incorporate the backreaction. Corrections to the thermal density matrix are also examined, and it is argued that to leading order in perturbation theory the effect of the backreaction is to modify the Bogoliubov transformation, but not in a way that restores information lost to the black holes.

The energy distributions of four 2+1 dimensional black hole solutions were obtained by using the Einstein and M{\\o}ller energy-momentum complexes. while $r \\to \\infty$, the energy distributions of these four solutions become divergence.

...concentration of the starch and the concentration of the amylase, respectively...procedure for bacterial amylases. REFERENCES Di CARLO...REDFERN, S. 1947 Alpha-amylase from Bacillus subtilis...showed that no tissue break- down of the black raspberries...

We present an exact static, spherically symmetric black hole solution to the third order Lovelock gravity with a string cloud background in seven dimensions for the special case when the second and third order Lovelock coefficients are related via $\\tilde{\\alpha}^2_2=3\\tilde{\\alpha}_3\\;(\\equiv\\alpha^2)$. Further, we examine thermodynamic properties of this black hole to obtain exact expressions for mass, temperature, entropy and also perform the thermodynamic stability analysis. We see that a string cloud background makes a profound influence on horizon structure, thermodynamic properties and the stability of black holes. Interestingly, the entropy of the black hole is unaffected due to a string cloud background. However, the critical solution for thermodynamic stability is being affected by a string cloud background.

We study the low temperature expansion of the first law of thermodynamics for near-extremal black holes. We show that for extremal black holes with non-vanishing entropy, the leading order contribution yields an expression for their extremal entropy in agreement with the entropy function result and the Cardy formula for the entropy of a two dimensional chiral conformal field theory (CFT). When their entropy vanishes due to the vanishing of a one-cycle on the horizon, such leading contribution is always compatible with the first law satisfied by a BTZ black hole. These results are universal and consistent both with the presence of local AdS2 and AdS3 near horizon throats for extremal black holes and with the suggested quantum microscopic descriptions (AdS2/CFT1, Kerr/CFT and EVH/CFT).

We study the thermodynamics and thermodynamic geometry of Park black hole in Ho\\v{r}ava gravity. By incorporating the ideas of differential geometry, we have investigated the thermodynamics using Weinhold geometry and Ruppeiner geometry. We have also analyzed it in the context of newly developed geometrothermodynamics(GTD). Divergence of specific heat is associated with the second order phase transition of black hole. Here in the context of Park black hole, both Weinhold's metric and Ruppeiner's metric well explain this phase transition. But these explanations depend on the choice of potential. Hence the Legendre invariant GTD is used, and with the true singularities in the curvature scalar, GTD well explain the second order phase transition. All these methods together give an exact idea of all the behaviors of the Park black hole thermodynamics.

We introduce analytical quantum gravity modifications of the production cross section for terascale black holes by employing an effective ultraviolet cut off $l$. We find the new cross sections approach the usual "black disk" form at high energy, while they differ significantly near the fundamental scale from the standard increase with respect to $s$. We show that the heretofore discontinuous step function used to represent the cross section threshold can realistically be modeled by two functions representing the incoming and final parton states in a high energy collision. The growth of the cross section with collision energy is thus a unique signature of $l$ and number of spatial dimensions $d$. Contrary to the classical black disk result, our cross section is able to explain why black holes might not be observable in LHC experiments while they could be still at the reach of ultra-high energy cosmic ray events.

Recently, it has been claimed that the back reaction of vacuum polarization on a black hole spacetime naturally regularizes infinities in the black hole entropy. We examine the back reaction calculation and find no such short-distance cut-off,in contradiction with these recent claims. Moreover, the intuitive expectation that the perturbative calculation breaks down near the event horizon is confirmed. The new surface gravity diverges and the metric is degenerate at the stretched horizon.

(continued) Page around the Aegean Sea. 39 Isopach map of the Middle-Upper Miocene sediments in the southwestern Black Sea Basin. 75 78 LIST OF TABLES TABLE I Internal seismic reflection configurations of the seismic stratigraphic units. Page 45...). Results of the most recent offshore research project (Finetti et al. , 1988), which covers the entire Black Sea basin, also support the back-arc basin model. In this study, 2D seismic reflection profiles are used to model the tectonic evolution...

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It has long been known that a maximally spinning black hole cannot be overspun by tossing in a test body. Here we show that if instead the black hole starts out with below maximal spin, then indeed overspinning can be achieved. We find that requirements on the size and internal structure of the test body can be met if the body carries in orbital but not spin angular momentum. Our analysis neglects radiative and self-force effects, which may prevent the overspinning.

Bekenstein-Hawking Black hole thermodynamics should be corrected to incorporate quantum gravitational effects. Generalized Uncertainty Principle(GUP) provides a perturbational framework to perform such modifications. In this paper we consider the most general form of GUP to find black holes thermodynamics in microcanonical ensemble. Our calculation shows that there is no logarithmic pre-factor in perturbational expansion of entropy. This feature will solve part of controversies in literatures regarding existence or vanishing of this pre-factor.

If the fundamental Planck scale is about a TeV and the cosmic neutrino flux is at the Waxman-Bahcall level, quantum black holes are created daily in the Antarctic ice cap. We reexamine the prospects for observing such black holes with the IceCube neutrino-detection experiment. To this end, we first revise the black hole production rate by incorporating the effects of inelasticty, i.e., the energy radiated in gravitational waves by the multipole moments of the incoming shock waves. After that we study in detail the process of Hawking evaporation accounting for the black hole’s large momentum in the lab system. We derive the energy spectrum of the Planckian cloud which is swept forward with a large, O(106), Lorentz factor. (It is noteworthy that the boosted thermal spectrum is also relevant for the study of near-extremal supersymmetric black holes, which could be copiously produced at the Large Hadron Collider.) In the semiclassical regime, we estimate the average energy of the boosted particles to be less than 20% the energy of the ? progenitor. Armed with such a constraint, we determine the discovery reach of IceCube by tagging on soft (relative to what one would expect from charged current standard model processes) muons escaping the electromagnetic shower bubble produced by the black hole’s light descendants. The statistically significant 5? excess extends up to a quantum gravity scale ?1.3??TeV.

The spin angular momentum $S$ of an isolated Kerr black hole is bounded by the surface area $A$ of its apparent horizon: $8\\pi S \\le A$, with equality for extremal black holes. In this paper, we explore the extremality of individual and common apparent horizons for merging, rapidly spinning binary black holes. We consider simulations of merging black holes with equal masses $M$ and initial spin angular momenta aligned with the orbital angular momentum, including new simulations with spin magnitudes up to $S/M^2 = 0.994$. We measure the area and (using approximate Killing vectors) the spin on the individual and common apparent horizons, finding that the inequality $8\\pi S extremality by computing the smallest value that Booth and Fairhurst's extremality parameter can take for any scaling. Using this lower bound, we conclude that the common horizons are at least moderately close to extremal just after they appear. Finally, following Lovelace et al. (2008), we construct quasiequilibrium binary-black-hole initial data with "overspun" marginally trapped surfaces with $8\\pi S > A$ and for which our lower bound on their Booth-Fairhurst extremality exceeds unity. These superextremal surfaces are always surrounded by marginally outer trapped surfaces (i.e., by apparent horizons) with $8\\pi Sextremality lower bound on the enclosing apparent horizon is always less than unity but can exceed the value for an extremal Kerr black hole. (Abstract abbreviated.)

We show that the previously obtained subtracted geometry of four-dimensional asymptotically flat multi-charged rotating black holes, whose massless wave equation exhibit $SL(2,\\R) \\times SL(2,\\R) \\times SO(3)$ symmetry may be obtained by a suitable scaling limit of certain asymptotically flat multi-charged rotating black holes, which is reminiscent of near-extreme black holes in the dilute gas approximation. The co-homogeneity-two geometry is supported by a dilation field and two (electric) gauge-field strengths. We also point out that these subtracted geometries can be obtained as a particular Harrison transformation of the original black holes. Furthermore the subtracted metrics are asymptotically conical (AC), like global monopoles, thus describing "a black hole in an AC box". Finally we account for the the emergence of the $SL(2,\\R) \\times SL(2,\\R) \\times SO(3)$ symmetry as a consequence of the subtracted metrics being Kaluza-Klein type quotients of $ AdS_3\\times 4 S^3$. We demonstrate that similar properties hold for five-dimensional black holes.

Advanced LIGO will be the first experiment to detect gravitational waves. Through superradiance of stellar black holes, it may also be the first experiment to discover the QCD axion with decay constant above the GUT scale. When an axion's Compton wavelength is comparable to the size of a black hole, the axion binds to the black hole, forming a "gravitational atom." Through the superradiance process, the number of axions occupying the bound levels grows exponentially, extracting energy and angular momentum from the black hole. Axions transitioning between levels of the gravitational atom and axions annihilating to gravitons produce observable gravitational wave signals. The signals are long-lasting, monochromatic, and can be distinguished from ordinary astrophysical sources. We estimate up to O(1) transition events at aLIGO for an axion between 10^-11 and 10^-10 eV and up to 10^4 annihilation events for an axion between 10^-13 and 10^-11 eV. In the event of a null search, aLIGO can constrain the axion mass as a function of the formation rate of rapidly spinning black holes. Axion annihilations are also promising for much lighter masses at future lower-frequency gravitational wave observatories, where we expect as many as $10^5$ events. Our projections for aLIGO are robust against perturbations from the black hole environment and account for our updated exclusion on the QCD axion of 6 * 10^-13 eV < ma < 2 * 10^-11 eV suggested by stellar black hole spin measurements.

The radiation emitted by a black hole (BH) during its evaporation has to have some degree of quantum coherence to accommodate a unitary time evolution. We parametrize the degree of coherence by the number of coherently emitted particles Ncoh and show that it is severely constrained by the equivalence principle. We discuss, in this context, the fate of a shell of matter that falls into a Schwarzschild BH. Two points of view are considered: that of a stationary external observer and that of the shell itself. From the perspective of the shell, the near-horizon region has an energy density proportional to Ncoh2 in Schwarzschild units. So, if Ncoh is parametrically larger than the square root of the BH entropy SBH1/2, a firewall or more generally a “wall of smoke” forms and the equivalence principle is violated while the BH is still semiclassical. To have a degree of coherence that is parametrically smaller than SBH1/2, one has to introduce a new sub-Planckian gravitational length scale, which likely also violates the equivalence principle. And so our previously proposed model which has Ncoh=SBH1/2 is singled out. From the external-observer perspective, we find that the time it takes for the information about the state of the shell to get re-emitted from the BH is inversely proportional to Ncoh. When the rate of information release becomes of order unity, the semiclassical approximation starts to break down and the BH becomes a perfect reflecting information mirror.

The discovery of cosmic acceleration has presented a unique challenge for cosmologists. As observational cosmology forges ahead, theorists have struggled to make sense of a standard model that requires extreme fine-tuning. This challenge is known as the cosmological constant problem. The theory of gravitational aether is an alternative to general relativity that does not suffer from this fine-tuning problem, as it decouples the quantum field theory vacuum from geometry, while remaining consistent with other tests of gravity. In this paper, we study static black hole solutions in this theory and show that it manifests a UV-IR coupling: Aether couples the space-time metric close to the black hole horizon, to metric at infinity. We then show that using the trans-Planckian ansatz (as a quantum gravity effect) close to the black hole horizon, leads to an accelerating cosmological solution, far from the horizon. Interestingly, this acceleration matches current observations for stellar-mass black holes. Based on our current understanding of the black hole accretion history in the Universe, we then make a prediction for how the effective dark energy density should evolve with redshift, which can be tested with future dark energy probes.

We study the fully nonlinear dynamical evolution of binary black hole data, whose orbital parameters are specified via the effective potential method for determining quasi-circular orbits. The cases studied range from the Cook-Baumgarte innermost stable circular orbit (ISCO) to significantly beyond that separation. In all cases we find the black holes to coalesce (as determined by the appearance of a common apparent horizon) in less than half an orbital period. The results of the numerical simulations indicate that the initial holes are not actually in quasi-circular orbits, but that they are in fact nearly plunging together. The dynamics of the final horizon are studied to determine physical parameters of the final black hole, such as its spin, mass, and oscillation frequency, revealing information about the inspiral process. We show that considerable resolution is required to extract accurate physical information from the final black hole formed in the merger process, and that the quasi-normal modes of the final hole are strongly excited in the merger process. For the ISCO case, by comparing physical measurements of the final black hole formed to the initial data, we estimate that less than 3% of the total energy is radiated in the merger process.

Celebrating Black History Month with DOE's Christopher Smith Celebrating Black History Month with DOE's Christopher Smith Celebrating Black History Month with DOE's Christopher Smith February 16, 2011 - 12:08pm Addthis Acting Assistant Secretary Smith Acting Assistant Secretary Smith Principal Deputy Assistant Secretary and Acting Assistant Secretary for Fossil Energy Throughout the month of February, we've been introducing remarkable African Americans who are working to advance the President's clean energy agenda. This week we're highlighting Christopher Smith, the Department's Deputy Assistant Secretary for Oil and Natural Gas in the Office of Fossil Energy. Below is a post he wrote that was featured on White House blog earlier this month. I'm lucky to have been raised by my parents, Raymond and Sue Ann Smith, who

Commemorating Black History: Contributions of African Americans to Commemorating Black History: Contributions of African Americans to the Manhattan Project Commemorating Black History: Contributions of African Americans to the Manhattan Project February 21, 2013 - 12:00pm Addthis July 20, 1944 July 20, 1944 September 21, 1944 September 21, 1944 March 24, 1944 March 24, 1944 June 27, 1944 June 27, 1944 July 20, 1944 September 21, 1944 March 24, 1944 June 27, 1944 The Department of Energy (DOE) commissioned an exhibit documenting the contributions of African Americans to the Manhattan Project at Hanford Reservation. The exhibit features pictures taken from the Hanford archives and oral histories of African Americans. The site was used to produce plutonium for the bomb that brought an end to World War II. During that era, people from all over the country came to Hanford, ultimately forming a

Historically Black Colleges and Universities Receive Funds for Historically Black Colleges and Universities Receive Funds for Fossil Energy Research Historically Black Colleges and Universities Receive Funds for Fossil Energy Research August 15, 2013 - 1:18pm Addthis Washington, D.C. - Five fossil energy-related projects that will help maintain the nation's energy portfolio while also providing educational and research training opportunities for tomorrow's scientists and engineers have been selected for funding by the U.S. Department of Energy (DOE). The funding opportunity to enhance scientific and technical understanding of conversion and utilization of fossil fuels is through the Office of Fossil Energy's National Energy Technology Laboratory (NETL). The DOE program involved is the Support of Advanced Fossil Resource Utilization

Department of Energy Office of Environmental Management: Department of Energy Office of Environmental Management: Historically Black Colleges and Universities July 2009 Department of Energy Office of Environmental Management: Historically Black Colleges and Universities July 2009 A presentation at the 10th Annual Small Business Conference and Expo, given by the Office of Environmental Management, to share information about the Office of Environmental Management and ways small businesses can help them meet their goals. Department of Energy Office of Environmental Management: Historically Black Colleges and Universities July 2009 More Documents & Publications Recovery Act Exceeds Major Cleanup Milestone, DOE Complex Now 74 Percent Remediated Office of Environmental Management: A Journey to Excellence Regional Small Business Summit Material

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The low-energy scattering of charged fermions by extremal magnetic Reissner-Nordström black holes is analyzed in the large-N and S-wave approximations. It is shown that (in these approximations) information is carried into a causally inaccessible region of spacetime, and thereby effectively lost. It is also shown that there is an infinite degeneracy of quantum black hole ground states, or "remnants," which store, but will not reveal, the information. A notable feature of the analysis, not shared by recent analyses of dilatonic black holes, is that the key physical questions can be answered within the weak coupling domain. We regard these results as strong evidence that effective information loss occurs in our Universe.

The evolving Laser Interferometer Space Antenna (eLISA) will revolutionize our understanding of the formation and evolution of massive black holes along cosmic history by probing massive black hole binaries in the $10^3-10^7$ solar mass range out to redshift $z\\gtrsim 10$. High signal-to-noise ratio detections of $\\sim 10-100$ binary coalescences per year will allow accurate measurements of the parameters of individual binaries (such as their masses, spins and luminosity distance), and a deep understanding of the underlying cosmic massive black hole parent population. This wealth of unprecedented information can lead to breakthroughs in many areas of physics, including astrophysics, cosmology and fundamental physics. We review the current status of the field, recent progress and future challenges.

We describe a simple method of extending AdS_5 black string solutions of 5d gauged supergravity in a supersymmetric way by adding Wilson lines along the string direction. Due to the specific form of 5d supergravity that features Chern-Simons terms, the existence of magnetic charges automatically generates conserved electric charges upon the addition of such Wilson lines in a 5d analogue of the Witten effect. Therefore we find a rather generic, model-independent way of adding electric charges to already existing solutions with no backreaction from the geometry or breaking of any symmetry. We use this method to explicitly write down a more general version of the Benini-Bobev black strings and comment on the implications for the dual field theory and the similarities with generalizations of the Cacciatori-Klemm black holes in AdS_4.

According to the no-hair theorem, astrophysical black holes are uniquely characterized by their masses and spins and are described by the Kerr metric. Several parametric spacetimes which deviate from the Kerr metric have been proposed in order to test this theorem with observations of black holes in both the electromagnetic and gravitational-wave spectra. Such metrics often contain naked singularities or closed timelike curves in the vicinity of the compact objects that can limit the applicability of the metrics to compact objects that do not spin rapidly, and generally admit only two constants of motion. The existence of a third constant, however, can facilitate the calculation of observables, because the equations of motion can be written in first-order form. In this paper, I design a Kerr-like black hole metric which is regular everywhere outside of the event horizon, possesses three independent constants of motion, and depends nonlinearly on four free functions that parameterize potential deviations from ...

We describe techniques for incorporating feedback from star formation and black hole accretion into simulations of isolated and merging galaxies. At present, the details of these processes cannot be resolved in simulations on galactic scales. Our basic approach therefore involves forming coarse-grained representations of the properties of the interstellar medium and black hole accretion starting from basic physical assumptions, so that the impact of these effects can be included on resolved scales. We illustrate our method using a multiphase description of star-forming gas. Feedback from star formation pressurises highly overdense gas, altering its effective equation of state. We show that this allows the construction of stable galaxy models with much larger gas fractions than possible in earlier numerical work. We extend the model by including a treatment of gas accretion onto central supermassive black holes in galaxies. Assuming thermal coupling of a small fraction of the bolometric luminosity of accreting...

We present exact spherically symmetric null dust solutions in the third order Lovelock gravity with a string cloud background in arbitrary $N$ dimensions,. This represents radiating black holes and generalizes the well known Vaidya solution to Lovelock gravity with a string cloud in the background. We also discuss the energy conditions and horizon structures, and explicitly bring out the effect of the string clouds on the horizon structure of black hole solutions for the higher dimensional general relativity and Einstein-Gauss-Bonnet theories. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms and/or background string clouds completely changes the structure of the horizon and this may lead to a naked singularity. We recover known spherically symmetric radiating models as well as static black holes in the appropriate limits.

We present a coherent picture of the quantum mechanics of black holes. The picture does not require the introduction of any drastically new physical effect beyond what is already known; it arises mostly from synthesizing and (re)interpreting existing results in appropriate manners. We identify the Bekenstein-Hawking entropy as the entropy associated with coarse-graining performed to obtain semiclassical field theory from a fundamental microscopic theory of quantum gravity. This clarifies the issues around the unitary evolution, the existence of the interior spacetime, and the thermodynamic nature in black hole physics--any result in semiclassical field theory is a statement about the maximally mixed ensemble of microscopic quantum states consistent with the specified background, within the precision allowed by quantum mechanics. We present a detailed analysis of information transfer in Hawking emission and black hole mining processes, clarifying what aspects of the underlying dynamics are (not) visible in sem...

The gravitational field outside of a nonrotating black hole is described using the Schwarzschild metric. The geodesic equations of the Schwarzschild metric are derived and those describing null and circular timelike orbits are discussed. Some numerical solutions of the null geodesic equations are shown. These depict photon trajectories which circle the black hole one or two times and then terminate at their emission points. Thus a sequence of ring?shaped mirror images is produced. An equation which gives the angle between the photon’s trajectory and the radial direction at the emitter is derived and applied to the numerical solutions. These results serve to illustrate how an observer ‘‘passes through’’ his or her mirror image at r=3 MG/c 2 as he or she moves toward a Schwarzschild black hole.

The heat capacities and the electric capacitances of charged Banados-Teitelboim-Zanelli (BTZ) black hole are first calculated. By using the equilibrium fluctuation theory of thermodynamics the second-order moments in three different ensembles are obtained, and it is found that in the microcanonical ensemble the extremal charged BTZ black hole is a critical point of the second-order phase transition. The critical exponents associated with some response coefficients satisfy the scaling law of the first kind and the effective spatial dimension is determined to be one from the scaling law of the second kind. The Ricci curvature scalar associated with the Ruppeiner thermodynamic metric is calculated, which suggests also that the effective spatial dimension of the charged BTZ black hole is one.

Black Friday Savings All Year 'Round Black Friday Savings All Year 'Round Black Friday Savings All Year 'Round November 21, 2011 - 3:58pm Addthis Chris Stewart Senior Communicator at DOE's National Renewable Energy Laboratory On Friday, shoppers across the country will flock to stores and retailers seeking the best bargains of the holiday season. Many will scour newspapers and online coupon sites seeking the deepest discounts and greatest deals. In case you'll be among these millions of consumers, don't forget buying energy efficient products will bring you savings all year 'round. When it comes to shopping for and comparing energy-efficient appliances and home electronics, look for the ENERGY STARÂ® and EnergyGuide labels. ENERGY STAR labels appear on appliances and home electronics that meet strict

Black-hole-neutron-star (BHNS) binary mergers are candidate engines for generating both short-hard gamma-ray bursts and detectable gravitational waves. Using our most recent conformal thin-sandwich BHNS initial data and our fully general relativistic hydrodynamics code, which is now adaptive mesh refinement capable, we are able to efficiently and accurately simulate these binaries from large separations through inspiral, merger, and ringdown. We evolve the metric using the Baumgarte-Shapiro-Shibata-Nakamura formulation with the standard moving puncture gauge conditions, and handle the hydrodynamics with a high-resolution shock-capturing scheme. We explore the effects of BH spin (aligned and antialigned with the orbital angular momentum) by evolving three sets of initial data with BH:NS mass ratio q=3: the data sets are nearly identical, except the BH spin is varied between a/M{sub BH}=-0.5 (antialigned), 0.0, and 0.75. The number of orbits before merger increases with a/M{sub BH}, as expected. We also study the nonspinning BH case in more detail, varying q between 1, 3, and 5. We calculate gravitational waveforms for the cases we simulate and compare them to binary black-hole waveforms. Only a small disk (<0.01M{sub {center_dot}}) forms for the antialigned spin case (a/M{sub BH}=-0.5) and for the most extreme-mass-ratio case (q=5). By contrast, a massive (M{sub disk}{approx_equal}0.2M{sub {center_dot}}) hot disk forms in the rapidly spinning (a/M{sub BH}=0.75) aligned BH case. Such a disk could drive a short-hard gamma-ray burst, possibly by, e.g., producing a copious flux of neutrino-antineutrino pairs.

According to general relativity a perturbed black hole will settle to a stationary configuration by the emission of gravitational radiation. Such a perturbation will occur, for example, in the coalescence of a black hole ...

While there is voluminous research on the Black male athlete, the literature does not touch on the notion of social responsibility. Thus, the purpose of this study was to garner perceptions of Black male athlete social responsibility (BMASR) from...

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of extra dimensions. Throughout, we have used the ATLAS fast simulation software [20] to give a description of a typical detector and we have used the full simulation [21] to verify the main results. 2. Black hole production and decay In the black hole... evolution from present energies is questionable. Also, comparison to Standard Model pro- cesses in the trans-Planckian regime would be difficult since perturbative physics would be suppressed. 4.2 The first stages of decay CHARYBDIS does not model...

There has been some recent controversy regarding the Ruppeiner metrics that are induced by Reissner-Nordstrom (and Reissner-Nordstrom-like) black holes. Most infamously, why does this family of metrics turn out to be flat, how is this outcome to be physically understood, and can/should the formalism be suitably modified to induce curvature? In the current paper, we provide a novel interpretation of this debate. For the sake of maximal analytic clarity and tractability, some supporting calculations are carried out for the relatively simple model of a rotating BTZ black hole.

The decay of a near-extremal black hole down to the extremal state is studied in the background field approximation to determine the fate of injected matter and Hawking pairs. By examining the behavior of light rays and solutions to the wave equation it is concluded that the singularity at the origin is irrelevant. Furthermore, there is most likely an instability of the event horizon arising from the accumulation of injected matter and Hawking partners there. The possible role of this instability in reconciling the D-brane and black hole pictures of the decay process is discussed.

We investigate the contributions of quantum fields to black hole entropy by using a cutoff scale at which the theory is described with a Wilsonian effective action. For both free and interacting fields, the total black hole entropy can be partitioned into a contribution derived from the gravitational effective action and a contribution from quantum fluctuations below the cutoff scale. In general, the latter includes a quantum contribution to the Noether charge. We analyze whether it is appropriate to identify the rest with horizon entanglement entropy, and find several complications for this interpretation, which are especially problematic for interacting fields.

We update our previous work on the description of twisted configurations for complex massless scalar field on the Kerr black holes as the sections of complex line bundles over the Kerr black hole topology. From physical point of view the appearance of twisted configurations is linked with the natural presence of Dirac monopoles that arise as connections in the above line bundles. We consider their description in the gauge inequivalent to the one studied previously and discuss a row of new features appearing in this gauge.

We investigate the contributions of quantum fields to black hole entropy by using a cutoff scale at which the theory is described with a Wilsonian effective action. For both free and interacting fields, the total black hole entropy can be partitioned into a contribution derived from the gravitational effective action and a contribution from quantum fluctuations below the cutoff scale. In general the latter includes a quantum contribution to the Noether charge. We analyze whether it is appropriate to identify the rest with horizon entanglement entropy, and find several complications for this interpretation, which are especially problematic for interacting fields.

We extend the study of the possibility to use the Schwarzschild black hole as a gravitational mirror to the more general case of an uncharged Kerr black hole. We use the null geodesic equation in the equatorial plane to prove a theorem concerning the conditions the impact parameter has to satisfy if there shall exist boomerang photons. We derive an equation for these boomerang photons and an equation for the emission angle. Finally, the radial null geodesic equation is integrated numerically in order to illustrate boomerang photons.

We extend the study of the possibility to use the Schwarzschild black hole as a gravitational mirror to the more general case of an uncharged Kerr black hole. We use the null geodesic equation in the equatorial plane to prove a theorem concerning the conditions the impact parameter has to satisfy if there shall exist boomerang photons. We derive an equation for these boomerang photons and an equation for the emission angle. Finally, the radial null geodesic equation is integrated numerically in order to illustrate boomerang photons.

We resume former discussions of the question, whether the spin-spin repulsion and the gravitational attraction of two aligned black holes can balance each other. Based on the solution of a boundary problem for disconnected (Killing) horizons and the resulting violation of characteristic black hole properties, we present a non-existence proof for the equilibrium configuration in question. From a mathematical point of view, this result is a further example for the efficiency of the inverse ("scattering") method in non-linear theories.

POLLEN ANALYSIS OF ANASAZI SITES AT BLACK MESA, ARIZONA A Thesis by ROBERT EARL MURRY, JR. Submitted to the Graduate College of Texas ASM IJnlversity in partial fulfillment of the requirement for the degree of MASTER OF ARTS August 1983... Major Subject: Anthropology POLLEN ANALYSIS OF ANASAZI SITES AT BLACK MESA, ARIZONA A Thesis by ROBERT EARL MURRY, "Jr. Approved as to style and content by: G en on H. Weir (Chairman of Committee) a . Sha e e er) Hug D. Wilson (Member) Va ghn...

In Parikh and Wilczek's original works, the laws of black hole thermodynamics are not referred and it seems that there is no relation between Hawking radiation via tunnelling and the laws of black hole thermodynamics in their works. However, taking examples for the R-N black hole and the Kerr black hole, we find that they are correlated and even consistent if the tunnelling process is a reversible process.

4: Vulnerability in the PDF distiller of the BlackBerry 4: Vulnerability in the PDF distiller of the BlackBerry Attachment Service for the BlackBerry Enterprise Server T-534: Vulnerability in the PDF distiller of the BlackBerry Attachment Service for the BlackBerry Enterprise Server January 13, 2011 - 2:30pm Addthis PROBLEM: Vulnerability in the PDF distiller of the BlackBerry Attachment Service for the BlackBerry Enterprise Server. PLATFORM: * BlackBerry Enterprise Server Express version 5.0.1 and 5.0.2 for Microsoft Exchange * BlackBerry Enterprise Server Express version 5.0.2 for IBM Lotus Domino * BlackBerry Enterprise Server versions 4.1.3 through 5.0.2 for Microsoft Exchange and IBM Lotus Domino * BlackBerry Enterprise Server versions 4.1.3 through 5.0.1 for Novell GroupWise * BlackBerry Professional Software version 4.1.4 for Microsoft Exchange and

Accretion of fields by black holes is a subject of great interest in physics. It is known that accretion plays a fundamental role in active galactic nuclei and in the evolution of black holes. Accretion of fundamental fields is often related to the study of absorption cross section. Basically all black holes for which absorption of fields has been studied so far present singularities. However, even within general relativity, it is possible to construct regular black holes: objects with event horizons but without singularities. Many physically motivated regular black hole solutions have been proposed in the past years, demanding the understanding of their absorption properties. We study the absorption of planar massless scalar waves by Bardeen regular black holes. We compare the absorption cross section of Bardeen and Reissner--Nordstr\\"om black holes, showing that the former always have a bigger absorption cross section for fixed values of the field frequency and of the normalized black hole charge. We also show that it is possible for a Bardeen black hole to have the same high-frequency absorption cross section of a Reissner--Nordstr\\"om black hole. Our results suggest that, in mid-to-high-frequency regimes, regular black holes can have compatible properties with black holes with singularities, as far as absorption is concerned.

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Measurement of Black Carbon and Particle Number Emission Factors from Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks Title Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks Publication Type Journal Article Year of Publication 2009 Authors Ban-Weiss, George, Melissa M. Lunden, Thomas W. Kirchstetter, and Robert A. Harley Journal Environmental Science and Technology Abstract Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel-fueled trucks driving through a 1 km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and COB2B concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were

CERTIFICATION of FINANCIAL RESPONSIBILITY Â­ USE BLACK INK ONLY Â­ This form is valid during your First or Given Middle Name Suffix COUNTRY OF CITIZENSHIP: DATE OF BIRTH: COUNTRY OF BIRTH: I plan qualifying dependents will accompany me: Name Date of Birth Country of Birth Country of Citizenship

Scalar field with generalized kinetic interactions metamorphoses depending on its field value, ranging from cosmological constant to stiff matter. We show that such a scalar field can give rise to temporal enhancement of the curvature perturbation in the primordial Universe, leading to efficient production of primordial black holes while the enhancement persists. If the inflation energy scale is high, those mini-black holes evaporate by the Hawking radiation much before Big Bang nucleosynthesis and the effective reheating of the Universe is achieved by the black hole evaporation. Dominance of PBHs and the reheating by their evaporation modify the expansion history of the primordial Universe. This results in a characteristic feature of the spectrum of primordial tensor modes in the DECIGO frequency band, opening an interesting possibility of testing PBH reheating scenario by measuring the primordial tensor modes. If the inflation energy scale is low, the PBH mass can be much larger than the solar mass. In this case, PBH is an interesting candidate for seeds for supermassive black holes residing in present galaxies.

@astron.berkeley.edu Abstract The first massive astrophysical black holes likely formed at high redshifts (z > 10 (Eddington) luminosity, and converts mass to radiation with an efficiency of = Mc2 /LEdd 10%) and using to link the evolution of quasars with that of dark matter halos condensing in a cold dark matter (CDM

We study gravitational lensing by a Reissner-Nordström black hole in the weak field limit. We obtain the basic equations for the deflection angle and time delay and find analytical expressions for the positions and amplifications of the primary and secondary images. Because of a net positive charge, the separation between images increases, but no change in the total magnification occurs.

......hole which accretes at a rate that is ultimately limited...intermittently at an average rate that is a universal function...that the mean accretion rate scales as M 1.5 t 6...sufficiently massive galaxies pass through a quasar phase...accretion discs|black hole physics|galaxies: active......

. Winter habitat use by black-capped vireos was best predicted by increasing values of slope and foliage cover, and by decreasing values of canopy cover and tree diameter. Vireo use plots characterized as thorn forest had greater foliage density, greater...

The Laser Interferometer Space Antenna (LISA) is designed to detect gravitational wave signals from astrophysical sources, including those from coalescing binary systems of compact objects such as black holes. Colliding galaxies have central black holes that sink to the center of the merged galaxy and begin to orbit one another and emit gravitational waves. Some galaxy evolution models predict that the binary black hole system will enter the LISA band with significant orbital eccentricity, while other models suggest that the orbits will already have circularized. Using a full 17 parameter waveform model that includes the effects of orbital eccentricity, spin precession, and higher harmonics, we investigate how well the source parameters can be inferred from simulated LISA data. Defining the reference eccentricity as the value one year before merger, we find that for typical LISA sources, it will be possible to measure the eccentricity to an accuracy of parts in a thousand. The accuracy with which the eccentricity can be measured depends only very weakly on the eccentricity, making it possible to distinguish circular orbits from those with very small eccentricities. LISA measurements of the orbital eccentricity can help constraints theories of galaxy mergers in the early universe. Failing to account for the eccentricity in the waveform modeling can lead to a loss of signal power and bias the estimation of parameters such as the black hole masses and spins.

We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known effect of superradiance. The corresponding power spectra for scalar fields show an enhancement with the number of dimensions, as in the non-rotating case. We compute the total mass loss rate of the black hole for a variety of black-hole angular momenta and bulk dimensions, and find that, in all cases, the bulk emission remains significantly smaller than the brane emission. The angular-momentum loss rate is also computed and found to have a smaller value in the bulk than on the brane. We present accurate bulk-to-brane emission ratios for a range of scenarios.

equal. In five dimensions, the most general charged rotating black hole solution has three charge and two rotation parameters. We obtain several special cases of the general solution. To be specific, we obtain the first example of a non-extremal rotating...

The motion of a black hole about the centre of gravity of its host galaxy induces a strong response from the surrounding stellar population. We treat the case of a harmonic potential analytically and show that half of the stars on circular orbits in that potential shift to an orbit of lower energy, while the other half receive a positive boost and recede to a larger radius. The black hole itself remains on an orbit of fixed amplitude and merely acts as a catalyst for the evolution of the stellar energy distribution function f(E). We show that this effect is operative out to a radius of approx 3 to 4 times the hole's influence radius, R_bh. We use numerical integration to explore more fully the response of a stellar distribution to black hole motion. We consider orbits in a logarithmic potential and compare the response of stars on circular orbits, to the situation of a `warm' and `hot' (isotropic) stellar velocity field. While features seen in density maps are now wiped out, the kinematic signature of black hole motion still imprints the stellar line-of-sight mean velocity to a magnitude ~18% the local root mean-square velocity dispersion sigma.

The authors investigate the heterogeneous adsorption of carbon monoxide and the concurrent catalytic and sorptive properties of palladium black from the standpoint of a comprehensive analysis of the infrared spectra of the reaction pathways and their various products as well as the pressure dependence of the line behavior at various wavelengths.

The polarized mm/sub-mm radiation from Sgr A* is apparently produced by a Keplerian structure whose peak emission occurs within several Schwarzschild radii (r_S=2GM/c^2) of the black hole. The Chandra X-ray counterpart, if confirmed, is presumably the self-Comptonized component from this region. In this paper, we suggest that sub-mm timing observations could yield a signal corresponding to the period P_0 of the marginally stable orbit, and therefore point directly to the black hole's spin a. Sgr A*'s mass is now known to be (2.6\\pm 0.2)\\times 10^6 M_\\odot (an unusually accurate value for supermassive black hole candidates), for which 2.7 minblack hole (a=0) should have P_0 ~ 20 min. The identification of the orbital frequency with the innermost stable circular orbit is made feasible by the transition from optically thick to thin emission at sub-mm wavelengths. With stratification in the emitter, the peak of the sub-mm bump in Sgr A*'s spectrum is thus produced at the smallest radius. We caution, however, that theoretical uncertainties in the structure of the emission region may still produce some ambiguity in the timing signal. Given that Sgr A*'s flux at $\

Nonlinear corrections are proposed to the discrete equispaced area spectrum of quantum black holes obtained previously in some quantisation schemes. It is speculated that such a modified spectrum might be related to the fine structure found using the loop quantum gravity approach.

for years. The amount of solar energy which can be absorbed by carbon black and transmitted to the air and the reduced solar radiation available inside the cloud. Such problems are to be expected when attempting particles in aerosol form spread artificially in the atmosphere to absorb solar radiation and hence

We examine the Zeroth Law and the Second Law of black hole thermodynamics within the context of effective gravitational actions including higher curvature interactions. We show that entropy can never decrease for quasi-stationary processes in which a black hole accretes positive energy matter, independent of the details of the gravitational action. Within a class of higher curvature theories where the Lagrangian consists of a polynomial in the Ricci scalar, we use a conformally equivalent theory to establish that stationary black hole solutions with a Killing horizon satisfy the Zeroth Law, and that the Second Law holds in general for any dynamical process. We also introduce a new method for establishing the Second Law based on a generalization of the area theorem, which may prove useful for a wider class of Lagrangians. Finally, we show how one can infer the form of the black hole entropy, at least for the Ricci polynomial theories, by integrating the changes of mass and angular momentum in a quasistationary accretion process.

In this paper we propose a stationary solution of Einstein's field equations describing Reissner-Nordstrom black hole in dark energy background. It is to be regarded as the Reissner-Nordstrom black hole is embedded into the dark energy solution producing Reissner-Nordstrom-dark energy black hole. We find that the space-time geometry of Reissner-Nordstrom-dark energy solution is Petrov type $D$ in the classification of space-times. It is also shown that the embedded space-time possesses an energy-momentum tensor of the electromagnetic field interacting with the dark energy having negative pressure. We find the energy-momentum tensor for dark energy violates the the strong energy condition due to the negative pressure, whereas that of the electromagnetic field obeys the strong energy condition. It is shown that the time-like vector field for an observer in the Reissner-Nordstrom-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity of the horizons for the embedded dark energy black hole. The characteristic properties of relativistic dark energy based on the de Sitter solution is discussed in an appendix.

We show that Weyl-invariant dilaton gravity provides a description of black holes without classical spacetime singularities. Singularities appear due to ill-behavior of gauge fixing conditions, one example being the gauge in which theory is classically equivalent to standard General Relativity. The main conclusions of our analysis are: (1) singularities signal a phase transition from broken to unbroken phase of Weyl symmetry, (2) instead of a singularity there is a "baby-universe" inside a black hole, (3) there is a critical mass after which reducing mass makes black hole larger as viewed by outside observers, (4) if a black hole could be connected with white hole through the "singularity", this would require breakdown of (classical) geometric description. The singularity of Schwarzschild BH solution is non-generic and so it it dangerous to rely on it in deriving general results. Our results may have important consequences for resolving issues related to information-loss puzzle. The theory we use is basically a completion of General Relativity, containing neither additional physical excitations nor higher-derivative terms, but requires physical scalar field such as Higgs field of Standard Model. Though quantum effects are still crucial and may change the proposed classical picture, a position of building quantum theory around regular classical solutions (without singularities) normally provides a much better starting point.

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One of the most spectacular predictions of the general theory of relativity is the black hole, an object that plays a central role in modern physics [1,2,3] and astrophysics [4,5]. Black holes are, however, plagued by fundamental paradoxes that remain unresolved to this day. First, the black hole event horizon is teleological in nature [6], which means that we need to know the entire future space-time of the universe to determine the current location of the horizon. This is essentially impossible. Second, any information carried by infalling matter is lost once the material falls through the event horizon. Even though the black hole may later evaporate by emitting Hawking radiation [7], the lost information does not reappear, which has the rather serious and disturbing consequence that quantum unitarity is violated [8]. Here we propose that the above paradoxes are restricted to a particular idealized model of collapse first studied in the 1930s [9, 10] in which the event horizon, which defines the boundary of...

...electromagnetic spectrum, as well as Chandra, X-ray Multi-Mirror Mission–Newton, Swift, and Fermi at higher energies...volumes to isolated galaxies, to accretion discs down to a few Schwarzschild radii in black hole merger simulations in general relativity...

We investigate static and dynamical n({>=}6)-dimensional black holes in Einstein-Gauss-Bonnet gravity of which horizons have the isometries of an (n-2)-dimensional Einstein space with a condition on its Weyl tensor originally given by Dotti and Gleiser. Defining a generalized Misner-Sharp quasilocal mass that satisfies the unified first law, we show that most of the properties of the quasilocal mass and the trapping horizon are shared with the case with horizons of constant curvature. It is shown that the Dotti-Gleiser solution is the unique vacuum solution if the warp factor on the (n-2)-dimensional Einstein space is nonconstant. The quasilocal mass becomes constant for the Dotti-Gleiser black hole and satisfies the first law of the black-hole thermodynamics with its Wald entropy. In the non-negative curvature case with positive Gauss-Bonnet constant and zero cosmological constant, it is shown that the Dotti-Gleiser black hole is thermodynamically unstable. Even if it becomes locally stable for the nonzero cosmological constant, it cannot be globally stable for the positive cosmological constant.

We compute the mass, angular momenta, and charge of the Goedel-type rotating black hole solution to five-dimensional minimal supergravity. A generalized Smarr formula is derived, and the first law of thermodynamics is verified. The computation rests on a new approach to conserved charges in gauge theories that allows for their computation at finite radius.

We consider general perturbations of a Schwarzschild black holes in the context of f(R) gravity. A reduced set of frame independent master variables are determined, which obey two closed wave equations - one for the transverse, trace-free (tensor) perturbations and the other for the additional scalar degree of freedom which characterise fourth-order theories of gravity. We show that for the tensor modes, the underlying dynamics in f(R) gravity is governed by a modified Regge-Wheeler tensor which obeys the same Regge-Wheeler equation as in General Relativity. We find that the possible sources of scalar quasinormal modes that follow from scalar perturbations for the lower multipoles result from primordial black holes, while higher mass, stellar black holes are associated with extremely high multipoles, which can only be produced in the first stage of black hole formation. Since scalar quasi-normal modes are short ranged, this scenario makes their detection beyond the range of current experiments.

Motivated by the idea of alpha-vacua in Schwarzschild spacetime, we studied the deformed spectrum of Hawking radiation. Such a deformation would leave signatures on the small black hole evaporation in LHC because their vacuum deviates from the Unruh state.

... , microscopic black holes have so far failed to appear inside the Large Hadron Collider (LHC), scientists there have revealed. The result, which will be posted this week on ... be posted this week on arXiv.org, comes as researchers make plans to keep the LHC running until the end of 2012, rather than 2011 as previously scheduled. The 27 ...

We analyze the fate of excitations in regions of closed string tachyon condensate, a question crucial for understanding unitarity in a class of black holes in string theory. First we introduce a simple new example of quasilocal tachyon condensation in a globally stable AdS/CFT background, and review tachyons' appearance in black hole physics. Then we calculate forces on particles and fields in a tachyon phase using a field theoretic model with spatially localized exponentially growing time dependent masses. This model reveals two features, both supporting unitary evolution in the bulk of spacetime. First, the growing energy of fields sourced by sets of (real and virtual) particles in the tachyon phase yields outward forces on them, leaving behind only combinations which do not source any fields. Secondly, requiring the consistency of perturbative string theory imposes cancellation of a BRST anomaly, which also yields a restricted set of states. Each of these effects supports the notion of a black hole final state arising from string-theoretic dynamics replacing the black hole singularity.

As the luminosity of an accreting black hole drops to a few percent of Eddington, the spectrum switches from the familiar soft state to a hard state that is well-described by a distended and tenuous advection-dominated accretion flow (ADAF). An ADAF is a poor radiator, and the ion temperature can approach 10^{12} K near the center, although the electrons are cooler, with their temperature typically capped at ~10^{9-11} K. The foundational papers predicted that the large thermal energy in an ADAF would drive strong winds and jets, as later observed and also confirmed in computer simulations. Of chief interest, however, is the accreting gas that races inward. It carries the bulk of the accretion energy as stored thermal energy, which vanishes without a trace as the gas passes through the hole's event horizon. One thus expects black holes in the ADAF regime to be unusually faint. Indeed, this is confirmed by a comparison of accreting stellar-mass black holes and neutron stars, which reside in very similar transient X-ray binary systems. The black holes are on average observed to be fainter by a factor of ~100-1000. The natural explanation is that a neutron star must radiate the advected thermal energy from its surface, whereas a black hole can hide the energy behind its event horizon. The case for an event horizon in Sagittarius A*, which is immune to caveats on jet outflows and is furthermore independent of the ADAF model, is especially compelling. These two lines of evidence for event horizons are impervious to counterarguments that invoke strong gravity or exotic stars.

The electromagnetic bremsstrahlung spectrum for the dipole which falling by a spiral orbit into the Schwarzschild black hole was found. The characteristic features in this electromagnetic spectrum can be used for determine of the black hole mass by the new way. This new way (if implemented) provides higher accuracy in determining of the black hole mass. Also these features in the spectrum can be used for determine of the certain characteristics in the black hole magnetosphere or in the accretion disk characteristics around the black hole. It is also shown that the asymptotic behavior of this spectrum (at high frequencies) is practically independent from the impact parameter of the falling dipole.

In the light of the "no-hair" conjecture, we revisit stable black holes in su(N) Einstein-Yang-Mills theory with a negative cosmological constant. These black holes are endowed with copious amounts of gauge field hair, and we address the question of whether these black holes can be uniquely characterized by their mass and a set of global non-Abelian charges defined far from the black hole. For the su(3) case, we present numerical evidence that stable black hole configurations are fixed by their mass and two non-Abelian charges. For general N, we argue that the mass and N-1 non-Abelian charges are sufficient to characterize large stable black holes, in keeping with the spirit of the "no-hair" conjecture, at least in the limit of very large magnitude cosmological constant and for a subspace containing stable black holes (and possibly some unstable ones as well).

The high cost of bleaching softwood mechanical pulps to 80% brightness with peroxide can be partly offset by recycling the unreacted peroxide in the effluent. However, the situation is complicated by the presence of dissolved organic material, aged silicate, and calcium extracted from the pulp. This study examines the effects of these materials on brightening efficiency. Dissolved organic material did not consume peroxide in subsequent cycles. Aged silicate stabilized peroxide as efficiently as fresh silicate. Interaction of silicate with calcium and magnesium caused silicon residue to precipitate on the fibers, with deposition increasing with the number of cycles. Calcium silicate adhered strongly to stainless steel, while magnesium silicate did not.

...brands of gold-containing cinnamon schnapps are available in the United States. Analysis of five 750-ml bottles of the Goldschlager brand showed 8 to 17 mg of gold flakes per bottle. The metallic flakes were 75 percent gold by weight, with 280 ?g of gold per deciliter dissolved in the liquid portion... To the Editor: Idiopathic lichen planus is a pruritic papulosquamous eruption that typically occurs in middle-aged persons. The estimated prevalence of this disorder is less than 1 percent, and its cause is unclear.1 Drug-induced lichen planus has been ...

Gathering data about black holes is difficult because we cannot see them. The gravity pull of the black hole is so strong that light, even at its great speed, cannot escape. We know black holes exist only because of celestial bodies around them, which, for example, change course or behave ''oddly'', sometimes being ''eaten'' by the crushing effect of the gravity-pulls from the black hole. For those who study negative behaviour at work, ''the bully'' is the parallel of black holes â?? almost invisible to us. We gain all our data regarding ''bullies'' from other people and events that happen around them. For example, when trying to detect pockets of bullying, personnel are directed to look for high exit rates of staff, long-term sickness due to stress and other side-effects that can be associated with a bullying situation. Finding and studying the bully is like trying to study black holes â?? we are often chasing scattered debris of complex data and shadows of the past. The study reported in this paper used data from subordinates on their managers' behaviour in order to classify how tough the managers were. A spectrum of ''toughness'' of management behaviour was generated. The managers' responses to a variety of measures including stress and mental health were examined as a way of trying to discriminate within the ''toughness'' spectrum. Results were non-significant. The study revealed differences in reporting of negative behaviour of managers and led to the suggestion that three types of manager behaviour might be present. The first is negative behaviour (typical of studies into bullying at work) that causes distress when it is present, but has no positive effect when it is absent â?? for example public humiliation. Another is spectrum behaviour that causes distress when it is absent and is enhancing to subordinates when it is present â?? for example being trusted with information. A third type was suggested as a result of the findings, but not included in this study. This third type could be termed positive behaviour (typical of leadership studies) and be enhancing when it is present, but not cause distress when it is absent â?? for example charismatic leadership. The results are discussed in the light of future research.

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July 24, 1997 July 24, 1997 DOE Selects Historically Black, Hispanic Universities To Receive Funding for Fossil Energy Research Projects As part of its efforts to encourage more participation by minority college students and teachers in its national energy program, the Department of Energy (DOE) has selected four coal and petroleum research projects to be carried out by student-teacher teams at historically black and minority universities in Virginia, Georgia, Maryland and New Mexico. The 1997 winning schools are: Hampton University, Hampton, VA, for research into chemical compounds that can clean sulfur pollutants from hot coal gases; Clark Atlanta University, Atlanta, GA, for a project to study novel chemicals that can aid in oil production; University of Maryland Eastern Shore, Princess Anne, MD, for studies of the spontaneous combustion of certain types of coals;

Christopher Smith Christopher Smith Celebrating Black History Month with DOE's Christopher Smith February 16, 2011 - 12:08pm Addthis Acting Assistant Secretary Smith Acting Assistant Secretary Smith Principal Deputy Assistant Secretary and Acting Assistant Secretary for Fossil Energy Throughout the month of February, we've been introducing remarkable African Americans who are working to advance the President's clean energy agenda. This week we're highlighting Christopher Smith, the Department's Deputy Assistant Secretary for Oil and Natural Gas in the Office of Fossil Energy. Below is a post he wrote that was featured on White House blog earlier this month. I'm lucky to have been raised by my parents, Raymond and Sue Ann Smith, who value education. As we celebrate Black History Month, I reflect on the

We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precurso...

We consider here the classic scenario given by Oppenheimer, Snyder, and Datt, for the gravitational collapse of a massive matter cloud, and examine its stability under the introduction of small tangential stresses. We show, by offering an explicit class of physically valid tangential stress perturbations, that an introduction of tangential pressure, however small, can qualitatively change the final fate of collapse from a black hole final state to a naked singularity. This shows instability of black hole formation in collapse and sheds important light on the nature of cosmic censorship hypothesis and its possible formulations. The key effect of these perturbations is to alter the trapped surface formation pattern within the collapsing cloud and the apparent horizon structure. This allows the singularity to be visible, and implications are discussed.

We present preliminary results in our long-term project of studying the evolution of matter in a dynamical spacetime. To achieve this, we have developed a new code to evolve axisymmetric initial data sets corresponding to a black hole surrounded by matter fields. The code is based on the coupling of two previously existing codes. The matter fields are evolved with a 2D shock-capturing method which uses the characteristic information of the GR hydro equations to build up a linearized Riemann solver. The spacetime is evolved with a 2D ADM code designed to evolve a wormhole in full general relativity. An example of the kind of problems we are currently investigating is the on axis collision of a star with a black hole.

Approximative analytic solutions of the Dirac equation in the Schwarzschild geometry are used for building the partial wave analysis of Dirac fermions scattered by black holes. The analytic expressions of the differential cross section and induced polarization degree are derived in terms of scattering angle, mass of the black hole, energy and mass of the fermion. We perform a graphical study of differential cross section analysing the forward/backward scattering (known also as glory scattering) and the polarization degree as functions of scattering angle. The graphical analysis shows the presence of oscillations in scattering intensity around forward/backward directions, phenomena known as spiral scattering. The energy dependence of the differential cross section is also established by using analytical and graphical methods.

We study the fluxes emitted by black holes when using dispersive field theories. We work with stationary one dimensional backgrounds which are asymptotically flat on both sides of the horizon. The asymptotic fluxes are governed by a 3x3 Bogoliubov transformation. The fluxes emitted by the corresponding white holes are regular and governed by the inverse transformation. We numerically compute the spectral properties of these fluxes for both sub- and superluminal quartic dispersion. The leading deviations with respect to the dispersionless flux are computed and shown to be governed by a critical frequency above which there is no radiation. Unlike the UV scale governing dispersion, its value critically depends on the asymptotic properties of the background. We also study the flux outside the robust regime. In particular we show that its low frequency part remains almost thermal but with a temperature which significantly differs from the standard one. Application to four dimensional black holes and Bose-Einstein condensates are in preparation.

Approximative analytic solutions of the Dirac equation in the Schwarzschild geometry are used for building the partial wave analysis of the Dirac fermions scattered by black holes. The analytic expressions of the differential cross section and induced polarization degree are derived in terms of scattering angle, mass of the black-hole, energy and mass of the fermion. We perform a graphical study of differential cross section analysing the forward/backward scattering (known also as glory scattering) and the polarization degree as functions of scattering angle. The graphical analysis shows the presence of oscillations in scattering intensity around forward/backward directions, phenomena known as spiral scattering. In addition, we find that the scattering probability increases significantly for fermions with large angular momentum. The energy dependence of the differential cross section is also established by using analytical and graphical methods.

In the context of studying black hole singularities by the AdS/CFT correspondence, we study the BTZ black hole by a scalar field propagating on it and the corresponding two-point Green functions. We explore how positions inside the horizon are encoded in the boundary theory. The main idea is to relate two different semi-classical approximations of the Green function and see how this indicates the bulk-boundary correspondence. From a key observation of Festucia and Liu, which is a frequency-geodesic identification, we deduce a geodesic approximation from the saddle point approximation. As an application, we find saddles of the Green function and hence their corresponding geodesics. The conclusion is that some of these geodesics do go inside the horizon. This gives the possibility of resolving the singularity from the boundary theory.

Based on the idea that tensor unparticles can enhance the gravitational interactions between standard model particles, potential black hole formation in high energy collisions is examined. Modifications to the horizon radius $r_H$ are derived, and the corresponding geometric cross-sections of such objects are calculated. It is shown that $r_H$ increases dramatically to the electroweak scale for masses $M_{BH} \\sim 1-10 $TeV, yielding a geometric cross-section $\\sigma_{BH}=\\pi r_H^2$ on the order of $leq 50$ pb. This suggests that unparticle physics provides a mechanism for black hole formation in future accelerators, without the requirement of extra spatial dimensions.

We study the mixed phase of charged AdS black hole and radiation when the total energy is fixed below the threshold to produce a stable charged black hole branch. The phase diagram of the mixed phase is demonstrated for both fixed potential and charge ensemble. In the dual gauge picture, they correspond to the mixed phase of quark-gluon plasma~(QGP) and hadron gas in the fixed chemical potential and density ensemble respectively. In the nuclei and heavy ion collisions at intermediate energies, the mixed phase of exotic QGP and hadron gas could be produced. The mixed phase will condensate and evaporate into the hadron gas as the fireball expands.

1 Statewide Imprisonment of Black Men in Wisconsin | A Resource Paper for Workforce Planning Statewide Imprisonment of Black Men in Wisconsin A resource paper for workforce planning prepared by Lois M for Workforce Planning 2. When prison records were examined for the state as a whole, they showed that by 2012

To have the correct picture of a black hole as a whole, it is of crucial importance to understand its interior. The singularities that lurk inside the horizon of the usual Kerr-Newman family of black hole solutions signal an endpoint to the physical laws and, as such, should be substituted in one way or another. A proposal that has been around for sometime is to replace the singular region of the spacetime by a region containing some form of matter or false vacuum configuration that can also cohabit with the black hole interior. Black holes without singularities are called regular black holes. In the present work, regular black hole solutions are found within general relativity coupled to Maxwell's electromagnetism and charged matter. We show that there are objects which correspond to regular charged black holes, whose interior region is de Sitter, whose exterior region is Reissner-Nordstroem, and the boundary between both regions is made of an electrically charged spherically symmetric coat. There are several types of solutions: regular nonextremal black holes with a null matter boundary, regular nonextremal black holes with a timelike matter boundary, regular extremal black holes with a timelike matter boundary, and regular overcharged stars with a timelike matter boundary. The main physical and geometrical properties of such charged regular solutions are analyzed.

We present an exact solution to the 5D Einstein-Maxwell-dilaton equations describing a static black hole on Taub-Nut instanton. By construction the solution does not possess a charge, but is magnetized along the compact dimension. As a limit we obtain a new regular solution representing a magnetized Kaluza- Klein monopole. We investigate the relevant physical properties and derive the Smarr-like relations.